Markus has appeared on behalf of Requested Persons (RPs) in extradition cases concerning both Part 1 (European Union) and Part 2 (non-European Union) territories.  His recent instructions include:

• EK v Türkiye – Instructed on behalf of a politically connected RP convicted of providing weapons to an armed terrorist organisation whilst still a child (led by Peter Caldwell KC).
   
• LE v USA – Sole counsel for a RP accused of leading an organised criminal group in a $720,000 international fraud. The extradition request followed a wide-ranging FBI investigation across multiple U.S. states. The RP faced a potential sentence of up to 127 years' imprisonment.
   
• TB v Spain – Ongoing challenge to extradition concerning a UK national convicted of importing over three tonnes of cannabis (valued at nearly €7 million). Expert evidence confirmed the RP suffers from PTSD following a rape by a Spanish prison guard.
   
• MO v Hungary – Extradition was resisted on multiple grounds, including the RP’s suicidality, risk of discriminatory treatment due to his Roma ethnicity, and concerns over Hungarian prison conditions. The two-day Extradition Hearing included live expert evidence from a Professor of Roma Studies, a psychiatrist, and a Hungarian legal expert.
   
• LL v Poland – Ongoing challenge to extradition concerning a Polish national suffering from a severe brain injury sustained whilst a child.
   
• OB v Sint Maarten – Assisted in an appeal focusing on the legal definition of “extradition” in a high-profile murder case.

In 2024, Markus undertook a secondment with the Crown Prosecution Service (CPS) Extradition Unit. As a Reviewing Lawyer, he handled requests from Part 1 territories, including those involving serious offences such as attempted murder and armed robbery. He also appeared as an advocate in Westminster Magistrates’ Court and the High Court. His time with the CPS provided valuable insight into international cooperation, including work with Liaison Prosecutors, the National Crime Agency (NCA), and the Home Office.

Markus’ article on the evidential significance of the reports of the Committee for the Prevention of Torture (CPT) in extradition hearings was published in Sweet & Maxwell’s European Human Rights Law Review in 2019. He has also delivered talks on Chinese extradition requests at Corker Binning and on extradition and war crimes at an international conference in Croatia.

Alongside his practice, Markus sits on the Committee of the Extradition Lawyers’ Association (ELA) and is an active member of the Defence Extradition Lawyers’ Forum (DELF).

Markus has a growing sanctions practice which stems from his previous secondment with the Office of Financial Sanctions Implementation (OFSI). 

During his time at OFSI, Markus gained valuable insight into the cross-government implementation and enforcement of sanctions. Based within the Russia Licensing Branch, he advised on licensing cases and policies governed by the Sanctions and Anti-Money Laundering Act 2018 (SAMLA) and a new and developing line of case law. He also delivered briefings to officials at the Foreign, Commonwealth & Development Office (FCDO) and the United States Department of State on joint sanctions projects. 

His recent work includes:

• Ongoing representation of a Designated Person in the first prosecution of an information offence under UK sanctions regulations. 

• Advised an individual challenging their designation by the FCDO on the basis of mistaken identity. 

• Advised a leading white-collar firm on compliance with OFSI’s annual frozen asset review process. 

• Assisted with a licence application for the release of frozen funds on behalf of a non-designated entity, involving a complex multi-jurisdictional payment route. 

• Advised a global strategic intelligence firm on the potential extraterritorial application of U.S. sanctions in relation to a client’s proposed divestment from a Middle Eastern jurisdiction.

In 2024 the Bar Council awarded Markus the International Professional and Legal Development Grant to attend a flagship sanctions conference in Washington DC. He has also co-authored articles on sanctions delisting and licensing for Westlaw. 

Markus is available to give presentations on sanctions matters. He is a member of the London Sanctions Advisers Association (LSAA). 

Markus has a busy Crown Court practice that has taken him across the country. Some of his notable cases include:

• R v AB – Successful defence of a cryptocurrency adviser in a private prosecution under the Financial Services Act 2012 for allegedly providing misleading investment advice. Markus’ abuse of process submissions forced his opponent (a King’s Counsel) to apply to quash the indictment. 
   
• R v PT – Ongoing representation of a Designated Person in the first prosecution of an information offence under UK sanctions regulations. 
   
• R v FH – Successful abuse of process challenge on behalf of an emergency worker accused of ULEZ-related fraud, resulting in the proceedings being discontinued.
   
• R v SC – Acquittal in a domestic burglary trial at Isleworth Crown Court in which the Crown relied on forensics and extensive bad character evidence. Praised by the presiding Recorder (Selva Ramasamy KC) for his closing speech who stated “this was a case where advocacy prevailed”.
   
• R v RJ – Led junior in a two-handed romance fraud trial at Guildford Crown Court in which the client was a serving Probation Officer. The fraud was valued at over £400,000 and impacted a total of 80 victims. The matter attracted the attention of national news outlets.   
   
• R v J – Secured a suspended sentence for a client convicted of Class A drug supply offences at Lewes Crown Court. The client, who initially faced an 8-count indictment, was arrested in a car containing the drugs and several weapons, including a machete and a stun gun. The Prosecution suggested these offences carried a starting point of 4.5 years in custody based on his “significant role” in the operation.
   
• R v C – Acquittal of man accused of sexually assaulting a woman in Zoo Bar in Leicester Square after a four-day trial at Southwark Crown Court. The client maintained his good character and avoided being added to the Sex Offenders Register.
   
• R v N – Acquittal in a bladed article trial at Southwark Crown Court for a chef of good character. 
   
• R v O – The Crown offered no evidence in respect of two Class A drug supply charges at Basingstoke Youth Court following seven hearings and Markus’ written representations highlighting two positive modern slavery determinations.
   
• R v B – Successful appeal of sentence and Football Banning Order (FBO) at Wolverhampton Crown Court for a public order offence arising from a clash between West Bromwich Albion and Millwall supporters at a match at The Hawthorns stadium.
   
• R v A – Appeared in a multi-handed three-day trial at Westminster Magistrates’ Court concerning anti-lockdown protestors charged with a public order offence. The trial received widespread media coverage and involved the cross-examination of the Political Editor of BBC Newsnight, Nicholas Watt.
   
• R v RT – Successful submission of no case to answer in an assault trial at St Albans Magistrates’ Court, preserving the client’s good character.

Markus has appeared on behalf of regulators and registrants at both interim and substantive hearings. He has a particular interest in regulatory proceedings arising from criminal investigations or convictions. 

His cases in this area include: 

• GMC v MH – Represented a Consultant Radiologist accused of dishonesty in the course of her practice at Chelsea and Westminster Hospital.
   
• GDC v LB – Persuaded a Professional Conduct Committee that his client’s fitness to practise dentistry was not impaired by reason of conviction and misconduct after a three-day hearing.
   
• NMC v RT – Appeared on behalf of the NMC at a seven-day Fitness to Practise Hearing. Markus secured a finding of impairment by reason of misconduct and ill health in respect of a nurse who was intoxicated at work from stolen opioids at the Royal Blackburn Hospital.
   
• BPS v LP – Advised Cognitive Behavioural Therapy (CBT) practitioner regarding his disclosure obligations in relation to three separate regulators following his arrest for sexual assault.

Outside of the healthcare context, Markus is a member of the Advocate Scheme for Advice and Representation of Football Referees. He accepts instructions in relation to regulatory matters arising in all sports. 

In 2023, Markus was instructed by HM Revenue & Customs (HMRC) to assist with the department’s preparation for the UK Covid-19 Inquiry. Through this work he gained insight into the government response to fraud relating to the Eat Out To Help Out and Coronavirus Job Retention schemes.

Markus was instructed as junior counsel in a pro bono inquest concerning the suicide of a 34-year-old man. Working alongside a team from the international law firm Arnold & Porter, his written submissions successfully persuaded the Assistant Coroner that the inquest should proceed with a jury. The Interested Persons included the local NHS Foundation Trust, the fire and rescue service, and police headquarters. Following the inquest, the Assistant Coroner issued a Prevention of Future Deaths (PFD) report, citing concerns over the lack of police training in mental health. The case received national media attention and was later featured as a pro bono case study.

Publications

‘To Be Understood: Are the Police Doing Enough to Help Victims of Crime with Low English Proficiency Report Crime?’ – Report commissioned by the Law Centres Network and Harrow Law Centre and compiled by Allen Overy Shearman Sterling LLP (2024). Markus was part of a team of criminal lawyers whose recommendations were published as part of the report.   

‘Sanctions Licensing’ (co-authored with Peter Caldwell KC) – Westlaw (2024)

'Are the Reports of The Council of Europe’s Committee for The Prevention of Torture (CPT) Fit for Purpose for Extradition Hearings Involving Issues of Mental Health?' – European Human Rights Law Review (Sweet & Maxwell) Volume 1 (2019)

‘Out of Sight, Out of Mind: The Mental Health Act and Prisoners’ Rights’ – UK Parliament’s Joint Committee for Human Rights (2017)

‘Migration and the Right to Education: The Case of Tigere’ – Gray’s Inn Student Law Journal (GIJ) Volume 9 (2017)

Presentations

‘Extradition, Diplomatic Assurances and War Crimes’ – Presentation at the Geoffrey Nice Foundation Master Class in Dubrovnik, Croatia (2021)

‘UK-China Extradition: The View from 2021’ – Presentation at Corker Binning (2021)