BHP v Município de Mariana: when foreign anti-suit proceedings can constitute criminal contempt

The Court of Appeal has allowed BHP's appeal in BHP Group (UK) Ltd & Anor v Município de Mariana & Ors [2026] EWCA Civ 294, holding that procuring a constitutional claim before Brazil's Supreme Federal Court — even one designed to halt English proceedings — did not amount to criminal contempt of court on the facts alleged.

The case arose from the collapse of the Fundão Dam in southeast Brazil on 5 November 2015, which killed 19 people and caused catastrophic environmental damage across a 400-mile river system. More than 600,000 claimants, including 46 Brazilian municipalities (the "Municipality Claimants"), pursued BHP in the Technology and Construction Court. At the centre of the appeal was whether BHP's procurement of a claim by the Brazilian Mining Association (IBRAM) before the STF — which sought to prevent the municipalities from litigating abroad at all — could be prosecuted as criminal contempt.

The IBRAM claim, a constitutional action known as an Arguição de Descumprimento de Preceito Fundamental (ADPF), sought declarations that Brazilian municipalities lacked standing to sue outside Brazil, together with injunctions requiring them to discontinue the TCC proceedings. BHP had funded the claim, filed four months before the stage 1 trial was due to begin, without notice to the municipalities or the court.

At first instance, Mr Justice Constable refused to strike out the contempt application, finding that the conduct was arguably improper interference with the administration of justice. BHP appealed.

Delivering the leading judgement, Lord Justice Popplewell confirmed the established framework: criminal contempt requires conduct carrying a sufficient risk of interference with the administration of justice, and the requisite intent need not be the sole or dominant purpose behind the conduct. Conduct that is otherwise lawful can still constitute contempt if undertaken for an improper purpose — a principle illustrated by R v Kellett [1976] and Attorney-General v Martin (1986).

However, the court drew a careful distinction between the criminal contempt jurisdiction and the anti-suit injunction (ASI) regime. ASI relief is grounded in the protection of private rights and interests; criminal contempt is concerned solely with the public interest in the administration of justice. These are not interchangeable concepts, and the availability of ASI relief does not determine the outer limits of contempt liability.

On the facts, the court held that the IBRAM claim could not — even on the assumed facts — amount to criminal contempt. The STF is a court of competent jurisdiction and the constitutional standing question was properly arguable before it. Had the claim been brought at the outset of the TCC proceedings, it would plainly have been unobjectionable: the STF would have been the natural forum to resolve a question of Brazilian constitutional law, and its determination would in practice have been dispositive of the issue in England. Comity required respect for that good faith invocation of foreign jurisdiction.

Crucially, the timing of the IBRAM claim — filed strategically four months before the stage 1 trial — did not alter this analysis. Although BHP's conduct was criticised as something that should have been raised with the court rather than pursued covertly, the mens rea and actus reus of the alleged contempt were no different from what they would have been had the claim been issued years earlier. Timing affected only the degree of consequential disruption, not the essential character of the conduct.

The judgement identifies five propositions governing the intersection of foreign anti-suit proceedings and criminal contempt. Most significantly, it holds that seeking foreign ASI relief can amount to criminal contempt only in exceptional circumstances — principally where the foreign proceedings are not brought in good faith, or where the conduct of the foreign state is so extreme as to deprive it of the comity ordinarily owed to civilised nations.

The case will be of considerable significance in any future litigation where a party is alleged to have weaponised foreign constitutional or anti-suit proceedings to derail English claims. It draws a principled boundary, grounded in comity and the distinct rationales of the ASI and contempt jurisdictions, that is likely to set a high threshold for such applications.

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