Clare Montgomery KC

Contact Clare: claremontgomery@matrixlaw.co.uk | +44 (0)20 7404 3447

Contact Clare's Practice Team (Team T): TeamT@matrixlaw.co.uk

Clare is a highly respected specialist in criminal, regulatory and fraud law, perhaps best known for her work on legally and factually complex cases. For the past decade Clare has dealt with the most demanding and difficult legal cases. She has featured in the starred category of KC’s recommended for crime and fraud for the whole of that period.

Formerly a member of the Attorney General’s Panel, Clare has also been concerned in a wide range of public law and due process cases both for and against the Government. Clare has been admitted in Northern Ireland and specially admitted in the courts of Antigua, the Bahamas, Bermuda, Brunei, Hong Kong, Mauritius and the Turks and Caicos Islands.

Competition and Regulation

Clare has long been concerned with legal issues in connection with market misconduct/insider dealing originally as standing counsel to the Department of Trade and Industry on insider dealing cases. She worked on early market misconduct cases, such as Guinness (R v Parnes and others) and the Morgan Grenfell insider dealing ring (R v Gray and others). In silk she has continued to advise on complex market misconduct and insider dealing issues working with prosecutors (including the FCA and HK SFC) as well as defending in these types of case, see for example HKSAR v Mo Yuk Ping and the British Airways/Virgin cartel prosecution. She provides incisive strategic advice in connection with market misconduct, insider dealing, and cartel investigations as well as prosecutions.

Directory Recommendations 2026: Business and Regulatory Crime

“A powerhouse, in terms of her razor-sharp focus and analytical skills. She deserves her stellar reputation.”

Governance, Investigations and Solutions

Clare is widely valued as a pre litigation adviser, providing strategic guidance and advice to companies and individuals caught up in regulatory and criminal investigations, particularly those with an international dimension and where civil, administrative and criminal law problems are present. Her recent case work includes Petrofac, Glencore and ENRC. She also led the FCA team in the prosecution of National Westminster Bank. She was GIR Investigations Professional of the Year 2022.

Directory Recommendations 2026: Financial Crime: Corporates

“Clare is a phenomenal practitioner.” “Clare is brilliant in all respects.”

Commercial law

Since taking silk, Clare has come to be valued as a trial advocate in complex civil disputes. She continues to work on civil fraud and arbitration cases both as an advocate and an adviser. She acted for News Group Newspapers in the Mobile Telephone Voicemail Interception litigation, for ENRC in its claims against the SFO and Decherts LLP and in Privatbank v Kolomoisky and others. She is valued for her ability to work in a team, her attention to detail and her skill as a cross examiner.

Directory Recommendations 2026: Fraud – Civil

“Clare … is a well-known advocate with a multi-jurisdictional criminal and civil practice who is used to dealing with difficult disputes. Much of her work is international in nature.” “Clare Montgomery is a superstar.”

Crime and Regulatory Law

Clare is able to take a case through from investigation to trial and appeal, as with the high profile investigation and prosecution of the Metropolitan Police Commissioner arising out of the death of Jean Charles de Menezes and the related proceedings in Strasbourg. She represents a range of prosecuting authorities, such as the FCA and SFO as well as acting for private clients and corporations.

She has a very strong appellate practice in the UK and abroad. She represented the Bar when the issue of barristers’ immunity arose in the House of Lords; she appeared for Sally Clark when Clark was finally cleared of murdering her two sons by the Court of Appeal in 2003. She was brought in to lead the argument for the defence when the Court of Appeal confirmed the dismissal of the pharmaceuticals case brought by the SFO in 2008. She has appeared in courts of appeal in Brunei, Bermuda and Hong Kong. In HKSAR v Andrew Lam she represented a solicitor charged with perverting the course of justice. She led on the trial and the appeal to HKCFA on behalf of Donald Tsang, the former Chief Executive of the HKSAR. She represented the Prime Minister of Mauritius, Pravind Jugnauth, in relation to conflict of interest in the UKPC in 2019. She defended Bernie Ecclestone on fraud charges in 2023. She has been involved in Encrochat cases in both the UK and Strasbourg courts.

Directory Recommendations 2026:  Crime

“As mightily impressive as her formidable reputation would suggest.”

Extradition and Mutual Assistance

Clare has extensive experience in extradition, international mutual legal assistance and international criminal law, representing both governments and individuals. She works with lawyers outside the UK on national and international criminal cases assisting with strategy and legal challenges. She represented Augusto Pinochet in the House of Lords. She advised the former Prime Minister of Thailand after he was ousted in a military coup. She led the prosecution team in relation to the extradition of the founder of Wikileaks and acted for Vijay Mallya and Nirav Modi in relation to Indian extradition requests. She represented Jack Warner on his appeal to the Privy Council. She is a co-author of The Law of Extradition and Mutual Assistance (4th Ed published by OUP, 2025). She regularly advises governments on crimes of universal jurisdiction.

Directory Recommendations 2026: Extradition

“Clare is a very good advocate and a walking law encyclopaedia.” “Clare Montgomery KC is known for her involvement in incredibly high-profile cases. She is particularly well versed in assisting individuals who are being sought for extradition by international governments as a result of alleged criminal offences.”

Fraud, Financial and Business Crime

Clare is presently advising several large companies in dealing with complex cross border issues including sanctions. Completed advice has enabled GSK to answer concerns raised by the MHRA in relation to clinical trials procedures by reference to EU and domestic regulation. She acted on behalf of BAE throughout the long running SFO investigation. She represented Tesco and G4S in connection with their deferred prosecution agreements. She also represented Petrofac and Glencore in concluding plea agreements with the SFO. She also prosecuted Nat West Bank on behalf of the FCA.

Directory Recommendations 2026: Business and Regulatory Crime

“A powerhouse, in terms of her razor-sharp focus and analytical skills. She deserves her stellar reputation.”

“A widely acclaimed, top-drawer silk whose talents are in considerable demand both at home and abroad. She acts for individuals and corporations, and is an elite practitioner whose advocacy skills are employed to great effect in appellate cases. Her practice has an international range and she has particular expertise in handling Hong Kong’s most high-profile financial crime matters. She is routinely called upon for her ability to handle the most complex fraud cases.”

Human Rights

Throughout her time in practice Clare has been closely connected with the development of human rights arguments in Strasbourg, from Soering though to Yukos related cases. She represented the Government of Cyprus before the Grand Chamber in Güzelyurtlu and others v Cyprus and Turkey [2019] ECHR 36925/07.

Directory Recommendation 2026: Civil Liberties & Human Rights

“Clare Montgomery is currently one of the stars of the Bar.” “Clare Montgomery is pragmatic, smart and strategic. She immediately knows what clients want.”

Public Law

Formerly a member of the Attorney General’s Panel, Clare has also been concerned in a wide range of public law and due process cases both for and against the Government in the UK and abroad.

Directory Recommendation 2026: Administrative & Public Law

“A powerhouse, in terms of her razor-sharp focus and analytical skills. She deserves her stellar reputation.”

“Clare is absolutely phenomenal. Her intellect is frightening and she is fierce in court. She is what a silk should be.” “Clare is the authority on a number of public law areas. She is a combination of charming and ruthless in court. She is pragmatic, smart and strategic with her advice.”

Proceeds of crime and asset forfeiture

Clare has been involved in the development of money laundering case law in Hong Kong including the landmark case of Pang Hung Fai.

She has a particular expertise in connection with regulatory obligations. She prosecuted Nat West Bank on behalf of the FCA in relation to offences under the Money Laundering Regulations.

She deals with Unexplained Wealth Orders and with civil recovery investigations and claims.

Directory Recommendation 2026: POCA Work & Asset Forfeiture

“She’s one of the best in white-collar crime and is in all the big cases. She has a huge practice, is very smart and works very fast. Judges love her.” “Clare Montgomery is excellent. She does very complex stuff.”

Protest law

Clare represented members of the Stansted 15 in their appeal to the Court of Appeal and appeared on the reference of the acquittal of the Colston statute protestors in the court of appeal. She defended Trudi Warner in the contempt claim brought by the Solicitor General v Warner.

Directory Recommendation 2026: Protest law

“Clare’s advocacy is direct, forceful and unpretentious.” “Clare is a standout advocate.”

Regulatory offences

Clare advises professionals caught up in complex regulatory investigations.

Serious crime

Clare is able to deal with the whole range of serious criminal cases. She defended Soldier A on a charge of murder of IRA leader Joseph McCann. She has been responsible  for appeals against a conviction for murder in the Bahamas. She is instructed in an Encrochat case that will test the boundaries of the existing case law.

Clare is committed to protecting and respecting your privacy. In order to provide legal services to her clients, including advice and representation services, Clare needs to collect and hold personal data. This includes her client’s personal data and the personal data of others who feature in the matter upon which she is instructed. To read Clare’s privacy notice in full, please see here.

DIRECTORY RECOMMENDATIONS