Sanctions and International Law

Providing experienced counsel in sanctions challenges and public law proceedings.

For more than a decade, Zaiwalla & Co has acted in challenges to sanctions and other restrictive measures imposed by UK, EU and international authorities. We represent corporations, financial institutions and individuals facing asset freezes, designations, travel bans and regulatory restrictions with serious commercial and personal consequences.

Our work includes judicial review proceedings, applications to set aside sanctions decisions and claims arising from unlawful government action. We have acted in matters before the highest courts in England and the European Union, including cases involving foreign state institutions and measures of geopolitical sensitivity.

Alongside contentious proceedings, we advise on sanctions exposure and compliance risk for clients operating in regulated and politically sensitive sectors. Our practice combines public law expertise with a clear understanding of international finance and state-led enforcement regimes.

Bank Mellat v HM Treasury

Zaiwalla & Co successfully challenged the UK Treasury’s designation of Bank Mellat under the UK’s Iran sanctions regime in a landmark Supreme Court judgment. The case, recognised by The Lawyer as one of the top 10 cases of 2013, involved the first closed material procedure ever conducted in the Supreme Court. The Court held that the financial restrictions imposed on the Bank were unlawful and disproportionate. In parallel proceedings before the European Court of Justice, the firm also secured the annulment of corresponding EU sanctions. The case remains a leading authority on proportionality, judicial scrutiny of executive sanctions powers and the conduct of closed hearings in national security litigation.

Zaiwalla & Co challenge $16m blocked as a result of sanctions

In Beneathco DMCC v R.J. O’Brien Ltd (Commercial Court, 2025), Zaiwalla & Co acts for a Dubai-based petroleum trader seeking recovery of US$16.5 million withheld by a UK broker following the trader’s designation under US sanctions. The dispute concerns whether a UK-incorporated entity, indirectly owned by a US parent, is legally prohibited from transferring funds held in a London account. Beneathco contends that the broker is not subject to US sanctions jurisdiction and that no legal barrier prevents payment under English law. The case raises important questions regarding the extraterritorial reach of US sanctions, the obligations of UK-regulated entities and the extent to which foreign sanctions may suspend contractual payment obligations before the English courts.

Zaiwalla & Co challenge $16m blocked as a result of sanctions

A Dubai-based petroleum products trader accused a U.K. broker on Tuesday of wrongly withholding $16.5 million from its cash account due to U.S. sanctions targeting Iran, at the beginning of a London trial.

Zaiwalla & Co defeats security for costs claim in novel £20m sanctions case

In Virgo Marine Inc and Nixie Marine v Reed Smith LLP and Barclays Bank PLC [2025] EWHC 1157 (Comm.), the High Court refused Reed Smith’s application for £6 million in security for costs against Zaiwalla & Co’s Dubai-based shipping clients. The claim arises from the freezing of approximately US$13.3 million held in escrow following Virgo Marine’s designation under US sanctions. Although Reed Smith later accepted that its London office was not subject to US sanctions and instructed Barclays to release the funds, the bank declined to do so. Virgo and Nixie commenced proceedings in negligence, breach of contract and breach of trust. Mr Justice Foxton rejected Reed Smith’s security application, holding that there was insufficient evidence that Barclays would refuse to comply with an English court order, describing the contrary evidence as “thin and unpersuasive.”

Zaiwalla & Co defeats security for costs claim in novel £20m sanctions case

In a judgment dated 14 May 2025, the English High Court refused an application by the English solicitors firm Reed Smith seeking £6m in security for costs from Dubai-based ship owners who claim the UK law firm negligently and unlawfully ordered its Bank, Barclays, to freeze the ship owners’ funds held by the firm in escrow after one of the Claimants was designated by the US Office of Foreign Assets Control (”OFAC”).

“Zaiwalla's attitude, communications, client focus, accuracy and quality are the firm's key strengths.”

“Sarosh Zaiwalla brings valuable experience to litigation; Leigh Crestohl has a strong intellect and good judgment; and Kartik Mittal works hard to achieve the right result for his clients.”

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“Zaiwalla is an unique outfit which has for decades handled heavyweight work for high-profile international clients.”

“The practice is marked by an in-depth assessment of legal issues and great attention to detail.”

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“Deep knowledge of case law and arbitration work.”

“Unique perspective on the law, ability to spot a weakness and execute strategies beneficial to their client.”

“The team absolutely punches above its weight- it regularly achieves success against larger firms not just in commodities arbitrations, but in appeals (including all the way up to the Supreme Court).”

“The team delivered consistently high-quality legal advice. Their client service was impressive, and they had to travel internationally as a team to meet a client in difficult circumstances.”