David O’Mahony

Offshore

David has been the lead external counsel in a number of substantial offshore investigations and associated litigation. These include: the largest ever criminal freezing order by value; the enforcement of the then largest kleptocracy civil forfeiture judgment obtained by the USDOJ; the only offshore financial crime case to reach the European Court of Human Rights; and the £ 100 million inducing breach of contract claim against the Jersey finance minister. In 2020 David represented Jersey in negotiating a US$ 300 million asset sharing Treaty between Jersey, the United States and Nigeria. In 2023 he was solely responsible for all the Attorney General’s written arguments in the three inter-locking appeals to the Privy Council in Tan Chi Fang v. Attorney General which considered issues of international jurisdiction and Sate Immunity as they applied to the freezing of a multi-jurisdictional offshore structure.

David managed and wrote all the arguments for the Jersey Attorney General’s Abacha cases (including Bhojwani and Doraville) which involved over 20 reasoned judgments at all levels of the court hierarchy (many of which are reported) and resulted in over US$ 500 million being returned to Nigeria.

In the course of his practice, David has been in 5 applications for permission to appeal to the Judicial Committee of the Privy Council, 11 appeals in the Jersey Court of Appeal, has had numerous instructions in Jersey, the Isle of Man (including cases in the Staff of Government Division) and Guernsey. He has received major instructions in Dubai (including acting alone in 3 inter-related arbitrations in the DIFC where he was admitted in the DIFC Court) and was junior counsel in the large corruption prosecution in the Turks and Caicos Islands. He has advised in a significant case in Hong Kong.

He has been instructed by the Jersey Financial Services Commissions (‘JFSC’) to conduct a 6 month regulatory investigation into the trusts arm of a major bank.

He is on the Serious Fraud Office ‘A’ Panel for Proceeds of Crime Act cases.

Notable Offshore cases

International

David has travelled widely. He did his first law degree in Australia. He has worked on the ground on cases in Thailand, Pakistan, India, Kenya, Nigeria and Switzerland. He has worked closely with the United States Department of Justice and the US State Department. He has given talks and chaired seminars for the United Nations Office on Drugs and Crime (UNODC) in Turkmenistan and Kazakhstan and spoken on crime and corruption issues in Ukraine, Brazil and Cyprus. He was part of a team working for the United Nations Development programme reviewing the draft Criminal Procedure Code for Sierra Leone. He has advised in cases involving a number of other jurisdictions including: Indonesia, Mongolia, Iran, Ukraine, Germany, Italy (in a case which involved the return of € 1.3 billion to that country), Denmark, Norway, the Democratic Republic of Congo and South Africa. He assists the CEELI institute in training judges in Eastern Europe and Africa.

His international work includes public and private international law issues (including issues of Sate Immunity), arbitration (he has been instructed in both commercial and investment arbitrations), civil fraud and proprietary claims (particularly where there is a linked criminal case), sanctions (he has advised on a wide range of sanctions regimes and on both the government and corporate sides of those issues), corruption (he has worked on the ground in a number of victim countries and negotiated a settlement with a large multi-national company) and international criminal law (he was instructed in a substantial in-country crimes against humanity investigation for which he wrote the report on fact and law, and is on the list of counsel at a number of international tribunals).

Academic and other

David has law degrees from the University of Queensland in Australia (where he also won the constitutional law prize) and the University of Cambridge (to which he won a full scholarship). He was awarded the Chapman Scholarship by the Inner Temple and tutored Public Law at the London School of Economics and Political Science (‘LSE’). He attended the Advanced Course in International Criminal Law and the Public International Law summer school at the Hague Academy of International Law and the Human Rights Law Summer School at the European University Institute in Florence. He is a member of the Royal Institute of International Affairs (Chatham House) and of the Regulatory Review Panel of the Bar Council.