Stefan Hyman


Stefan’s practice comprises extradition & INTERPOL work, European criminal law, post-Brexit security cooperation, UK sanctions law and English criminal law. Stefan sits on the Bar Council’s European Committee where he specialises in justice and security issues. He serves as a UK Delegate to the Council of Bars and Law Societies of Europe’s (CCBE) Criminal Law Committee.

Stefan is well-liked by solicitors and clients who value his easy manner and pragmatism. He is ranked in the Legal 500 as a Leading Junior in the field of International Crime and Extradition (2024), “He is imaginative and insightful and has a very energetic, charming court manner – judges like him”. He frequently publishes and gives seminars on extradition law and has contributed to official reports on the state of UK/EU security cooperation. He is qualified to represent members of the public directly in accordance with the Bar Council’s Direct Access Scheme.


Extradition & INTERPOL: Stefan represents parties at first instance and on appeal to the Administrative Court and UK Supreme Court. He is an expert at making technical challenges to extradition requests and advancing human rights arguments. As a fluent Spanish speaker, Stefan has particular interest in cases emanating from Spain and Latin America. Stefan has recent expertise in successfully defending Belgian, Cypriot and Greek cases and appearing for governments in Canadian, Swiss and US cases. Stefan is appointed to the CPS’ Extradition Panel at Level 3.

Stefan advises on ancillary matters to extradition, including sentence transfer, instructing a lawyer in the requesting state, alternatives to surrender, recognition of time spent on bail in the UK in the requesting state, and seeking withdrawal of domestic warrants/SIS II alerts. He assists those making applications to INTERPOL’s Commission for the Control of Files (CCF) to confirm what data INTERPOL holds and to seek correction or deletion thereof.

EU criminal law: Stefan is an expert on the justice and law enforcement provisions in the UK/EU Trade and Co-operation Agreement 2020. He advises on matters including mutual legal assistance, criminal record exchange, Prüm and evidence admissibility. His expertise includes other EU justice and human affairs measures, including the European arrest warrant (EAW), the European investigation order (EIO), the European Public Prosecutor’s Office (EPPO) and procedural rights. As such, he is well-placed to advise on cross border investigations.

UK sanctions law: Having been seconded to the Foreign, Commonwealth and Development Office’s (FCDO) sanctions legal team in 2023/4, Stefan will receive instructions on UK sanctions cases following his return to Chambers. His expertise includes the operation of autonomous and mixed regimes under the Sanctions and Anti-Money Laundering Act 2018 (SAMLA); making information requests, administrative reviews (section 23) and court reviews (section 38); implementation of UN sanctions in UK law; licensing under SAMLA, including the interaction between the UK, Crown Dependencies and Overseas Territories, and the nexus between UK and EU restrictive measures.

UK criminal law: Stefan prosecutes and defends in the Crown Court receiving instructions in cases involving (dis)honesty, drugs, violence, fraud, and money laundering. He has an interest in evidential and jurisdictional issues and is well-versed in the disclosure regime under the Criminal Procedure and Investigations Act 1996 (CPIA). Stefan is appointed to the CPS’ General Crime (Level 2), Specialist Fraud (Level 2) and Special Crime (Level 2) panels.

Notable cases

Bertino v Public Prosecutor’s Office, Italy [2024] UKSC 9; [2024] 1 WLR 1483

To be deliberately absent from trial within the meaning of section 20(3) of the Extradition Act 2003, a requested person must have knowingly and intelligently waived his/her right to attend trial in person. This normally requires express notification of the date/place of trial and that it may proceed in absence. Only in extreme circumstances may a court find that a requested person who has not been so notified could have reasonably have foreseen the consequences of his/her conduct so that an extradition court may be sure of unequivocal waiver.

Read the judgment here

Merticariu v Judecatoria Arad, Romania [2024] UKSC 10; [2024] 1 WLR 1506

A right to a retrial within the meaning of section 20(5) of the Extradition Act 2003 confers an entitlement to receive a retrial in the requesting state and not an opportunity to apply for one. The only limitation to the entitlement may be procedural, such as a requirement to request within a specified time limit. The responses received to the requests for further information demonstrated that a judicial authority in Romania had a discretion to grant a retrial and therefore did not fulfil the requirements of section 20(5) of the Extradition Act 2003.

Read the judgment here

Paczkowski v Regional Court of Szczecin, Poland [2023] EWHC 1489 (Admin)

A party to appellate proceedings under the Extradition Act 2003 may reapply for the admission of evidence at an appeal hearing where a judge has refused the application on the papers. The admissibility of evidence is a substantive matter and not a case management decision. Under r.50.17 Crim PR, only case management decisions can be made on the papers.

Read the judgment here

Ristin v. Court of Timisoara, Romania [2022] EWHC 3163 (Admin)

Stefan represented a Romanian judicial authority in an appeal in which the High Court considered whether the first instance judge was correct to find that the requested person was a fugitive at common law. Fordham J considered the different appellate authorities on fugitive status and concluded that a lack of a prohibition on a requested person from leaving the requesting state before a conviction becomes final does not preclude a finding of fugitivity. The Court also considered how it should measure the seriousness of conduct where the penalty imposed in the requesting state is substantially different and greater than in comparable circumstances in England & Wales and when, per §13 of Poland v Celinski [2016] 1 WLR 551, the Court may examine what sentence a domestic court would have imposed.

Fedorowicz v. Prosecutor General’s Office, Lithuania [2022] EWHC 3088 (Admin)

Stefan represented a Lithuanian judicial authority in an appeal concerning extraterritorial dual criminality (section 64(4) EA). The case turned on the meaning and scope of section 45 of the Serious Crime Act 2015 through which Parliament incorporated the offence created in Article 5 of the UN (Palermo) Convention on Transnational Organized Crime 2000, ergo participation in an organised crime group. To furnish a domestic court with jurisdiction to try a defendant in equivalent circumstances, Fordham J held that a person must participate in some of an organised crime group’s activities in England & Wales; it was not enough that another member of the organised crime group participated in activities in England & Wales whilst the person’s own activities all took place abroad.

Court of Appeal of Thessaloniki v Hysa and Others [2022] EWHC 2050 (Admin)

Stefan successfully defended a CPS appeal against the District Judge’s decision to discharge his client due to insufficient personal space in multioccupancy cells at Thessaloniki (Diavata) Prison. At first instance, the three requested persons, all of whom were remanded in custody, were discharged after the Greek authorities failed to answer the District Judge’s Aranyosi request within the timeframe given. The District Judge’s request followed an express concession some six months previously that conditions at Diavata Prison were incompliant with Article 3 ECHR. Four days after discharge, a document which purported to serve as an assurance was received. The CPS appealed under section 28 EA. In its decision, the Court considered: (i) the ambit of judicial review versus a statutory appeal under section 26 or 28 EA where a ruling resulted in a final order, be it discharge or extradition; (ii) the standard of review when seeking to make “a collateral attack” on a case management decision which resulted in a final order; (iii) the “relevant question” upon remittal under section 29(5) EA, particularly where multiple human rights challenges are raised.

Ziembinski v. Regional Court of Plock, Poland [2022] EWHC 693 (Admin)/ Gorak v. Regional Court in Poznan, Poland [2022] EWHC 671 (Admin)

Stefan represented Polish judicial authorities in two cases which considered the requisite approach to Article 8 proportionality assessments where there is uncertainty concerning whether the SSHD will permit a requested person to re-enter the UK after extradition or even revoke a grant of settled status.

Bullman v. High Court of Dublin (Ireland) [2022] EWHC 194 (Admin)

Stefan represented an Irish court in an extradition request for a British man accused of raping a partner twenty years ago. The requested person had a series of acute physical problems and learning difficulties which meant that the Court had to consider whether extradition would be oppressive. There were significant delays owing to the fact that the complainant suffered a fall and lost her memory for several years. The case considered reporting restrictions / anonymity for complainants of sexual offences in extradition proceedings. The Judge considered the circumstances in which the Court can and should anonymise the name of a requested person where he would be afforded such anonymity in the requesting state.

R (Salomon) v. Westminster Magistrates’ Court [2022] EWHC 83 (Admin)

Led by James Hines KC, Stefan represented the CPS in a recent Administrative Court case which considered whether the High Court or an extradition ticketed judge at Westminster Magistrates’ Court can review the taking of consent when it is alleged that incorrect or insufficient legal advice was given.

Ekwoge v. Central District Court in Buda (Hungary) [2021] EWHC 3163 (Admin)

Stefan represented a Hungarian court seeking the requested person’s extradition to stand trial in respect of money laundering offences. The requested person, who is of Cameroonian/African descent, claimed that the systematic racism and hostile environment within Hungary and, in particular, the criminal justice system and prison system, would result treatment contrary to A3 ECHR. The considered recent political developments in Hungary and adverse findings made by various UN bodies and NGOs. Permission to appeal was refused at an oral hearing.

Litwinczuk and Others v. Poland [2021] EWHC 2735 (Admin)

Stefan represented one of the requested persons in the first challenge to (general) prison conditions in Poland since 2012. The Court considered expert evidence and open source material which suggested that some of those detained in Poland had fewer than three metres square of personal space. Nevertheless, the Court did not find sufficient cause to seek further information under the Aranyosi process.

Balaz v. District Court of Zloven (Slovakia) [2021] EWHC 1862 (Admin)

Stefan represented a Slovak judicial authority where he successfully argued that the POCA money laundering (s. 327-329) offences are extra-territorial in nature and the correct test for purposes of dual criminality is whether the conduct constitutes an offence and not whether it would be charged in England and Wales in similar circumstances.

MW v. High Court of the Republic of Ireland

Stefan appeared on behalf of the Irish judicial authority at first instance and on appeal in a series of cases concerning the validity of Irish extradition requests in England and Wales following Exit Day and IP Completion Day. The challenge, which was raised under the heads of validity and abuse of process, concerned the Republic’s general opt out of the Area of Freedom, Security and Justice per Protocol 21 to the TEU/TFEU and the Union’s competence to reach agreements on behalf of Ireland in these specific areas. Owing to a ruling of the Grand Chamber of the CJEU in November 2021, which confirmed the Union’s competence to conclude law enforcement and security cooperation measures on behalf of Ireland in both the UK/EU Withdrawal Agreement 2019 and UK/EU Trade and Cooperation 2020, the point did not require final adjudication in this jurisdiction.

Hungary v DB

Stefan represented a requested person in one of the first Part 1 cases in which the underlying international instrument was the UK/EU Trade and Cooperation Agreement 2020 instead of the EAW Framework Decision. Given that his client was sought for purposes of prosecution and remanded in custody, Stefan challenged how UK judges should approach the principle of proportionality per Art. 597 of the TACA and the effect of the new joint EU/UK declaration on proportionality.

Luxembourg v MM

Stefan represented an individual sought in Luxembourg on suspicion of various offences of fraud. Stefan challenged whether the EAW provided sufficient detail to be considered valid and whether some conduct met the dual criminality test. He also argued that the Luxembourg authorities had not made a charging decision. Stefan succeeded in securing his client’s discharge in respect of some offences. The case is currently on appeal in relation to the others.

Greece v AN

Stefan represents a requested person accused of homicide in Greece. He challenges extradition on human rights grounds including inadequate prison conditions as a result of chronic overcrowding and high rates of inter-prisoner violence within the Greek prison estate (A3 ECHR), restrictions on the requested person’s right to apply for bail if extradited (A5 ECHR) and the Greek prosecutor’s failure to conduct an adequate investigation into the alleged criminality (A6 ECHR). He secured a discharge at first instance. The Greek authorities have appealed the district judge’s decision.

Spain v CB

Stefan represented a Spanish court which sought the requested person’s extradition in respect of a series of violent robberies committed when he was seventeen. By the time at which the EAW was issued, the requested person had turned eighteen and the case turned on whether the wrong court in Spain had issued the EAW, thereby, rendering it invalid ab initio. Stefan successfully relied on recent Court of Justice and domestic case law concerning the circumstances in which a decision to issue an EAW can be challenged in the Executing State to persuade the judge not to review the circumstances in which the EAW.

Operation Banjax

Instructed by the Serious Fraud Division as a disclosure junior on a 13-handed cheat of the public Revenue involving a VAT loss of £34m. Given the volume of material, Stefan was instructed to attend trial. 9 defendants convicted. Confiscation proceedings are on-going. Southwark Crown Court.

R v IK

Advised on the new ‘assaulting an emergency worker’ offence as well as the powers conferred on PCSOs following a recent change in legislation. CPS offering no evidence on the indictment. Snaresbrook Crown Court.

R v SF

Following guilty pleas at PTPH to six dwelling burglaries and threats to cause criminal damage, Stefan obtained a sentence of four years’ custody for a prolific domestic burglar accused of a series of category one offences. Snaresbrook Crown Court.

Read more Notable cases

Directories recognition

  • Chambers & Partners (2024) – Extradition (Band 3).
  • Chambers & Partners (2023) – Extradition (Band 4): "Stefan is really thorough in his research and always on top of the law”; "He is a fantastic advocate who goes the extra mile every time."
  • Legal 500 (2024) – International Crime and Extradition (Band 3): “He is imaginative and insightful and has a very energetic, charming court manner – judges like him”.
  • Legal 500 (2023) – International Crime and Extradition (Rising Star): “Stefan knows his extradition and public law really well”.


  • Honourable Society of Lincoln’s Inn, Buchan Prize for BPTC Result (2015).
  • Honourable Society of Lincoln’s Inn, Lord Denning Scholarship for the BPTC (2014).
  • Organization of American States, Best Participant in the Model OAS (2010).
  • University of Edinburgh, Special Distinction in Spoken Spanish (2009)


Crimeline (2023) & DELF Newsletter (2023), Two important EAW decisions and what they meant to us

Crimeline (2022), Detention conditions and release mechanisms: the approach to countries outside the Council of Europe 

Crimeline (2022), Meanwhile in Europe…: a summary of the Court of Justice’s recent case law on the EAW 

Crimeline (2022): How to interpret the Extradition Act 2003? From compatible to conforming interpretation to incorporation

Crimeline (2022): Appeals procedure in extradition cases

Crimeline (2021): Marosan V Romania (2021) EWHC 3098 and an underlying theme: how to ascertain the EU law obligations of foreign courts

DELF Newsletter (2021): Recent Developments in Appeal Procedure

Crimeline (2021): Zabolotnyi in the Supreme Court: three takeaways and a look to the future

Crimeline (2020): Extradition to the EU-27 under the UK/EU Trade and Cooperation Agreement: similarities and ten key differences (updated) (with Jonathan Swain)

Crimeline (2020): Looking beyond the Transition Period: will there be surrender? (with Jonathan Swain)


  • English (native)
  • Spanish (fluent)
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PROFILE: Stefan Hyman

Legal 500, 2024 Chambers UK, 2024

Year called




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Human rights law


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Direct access



020 7489 2727


City Law School (2015), Bar Professional Training Course, Outstanding.

City Law School (2015), Graduate Diploma in Law, Commendation.

King’s College London (2010), MA in War Studies, Distinction.

University of Edinburgh (2009), MA (Hons.) in European History and Spanish, First-class with Honours.


The Honourable Society of Lincoln's Inn

The Criminal Bar Association

Defence Extradition Lawyers' Forum

European Criminal Bar Association


CPS Extradition Panel (Grade 3)

CPS Panel (Grade 2)

CPS Fraud Panel (Grade 2)

CPS Serious Crime Panel (Grade 2)

European Committee, Bar Council

CCBE Criminal Law Committee (UK Delegation)


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