David O’Mahony

David O’Mahony specialises in cases in which international issues arise.

He has particular experience in offshore issues and is the head of the Offshore and International team in Chambers.

His practice has ranged across this field of the law being instructed in cases involving money laundering and criminal fraud, civil and commercial law (particularly fraud), arbitration (both commercial and investment arbitration), domestic and international financial regulation and international crime. He advises on public and private international law and international criminal law.

He has deep knowledge of the law of bribery and corruption. He has acted for and against companies as well as individuals in corruption cases. He has also acted in parallel civil and criminal proceedings. He has acted for a number of developing world governments in corruption investigations and negotiated a settlement agreement with one of the world’s largest companies. In 2020 he acted for Jersey in negotiating a landmark $ 300 million asset sharing agreement with the United States and Nigeria.

David also advises on sanctions related issues (including in an offshore context). He has advised on a number of the sanctions regimes including in relation to Russia/Ukraine, North Africa and Iran. He has advised on historic sanctions issues. He has acted on both the government and corporate side of sanctions issues.

In the field of International Criminal Law, he was instructed in a major, in country, crimes against humanity investigation and wrote the major report on both fact and law.

David has been instructed in cases in the UK, Africa, the Caribbean, Central Asia, all the Crown Dependencies, the Gulf, the Indian sub – continent, Hong Kong and South East Asia. He has been called to the bar in Australia, the DIFC courts and the TCI. He is on the list of counsel at the International Criminal Court and the Special Tribunal for Lebanon in the Hague, and has acted successfully for the UK government in the European Court of Human Rights. He has appeared as junior counsel in commission hearings in the Indian courts and in the Privy Council. He is on the Serious Fraud Office ‘A’ Panel for Proceeds of Crime Act cases.

He has worked with Swiss investigating magistrates and the USDOJ as well as public authorities in the developing world.

He has given talks for the United Nations Office on Drugs and Crime (UNODC) in Turkmenistan and Kazakhstan and was instructed by the UNDP to assist in its review of the draft Criminal Procedure Act for Sierra Leone.

David has degrees from Cambridge University and the University of Queensland (Australia), and tutored Public Law at the London School of Economics and Political Science (‘LSE’). He attended the Hague Academy of International Law Advanced Course in International Criminal Law and the European University Institute Human Rights Law summer school.