In the French-language decision A and B v International Biathlon Union (IBU), 4A_620/2009 (7 May 2010), the Federal Tribunal ruled on a petition to set aside an interim award by the Court of Arbitration for Sport (CAS). In the award, the CAS had confirmed a two-year ban imposed on A and B, two biathletes of international standing who had tested positive for recombinant Erythropoietin (rEPO).

A and B had, inter alia, based their petition before the Federal Tribunal on Article 190(2)(e) of the Swiss Private International Law Act (PILA), which permits an award to be set aside if it is incompatible with public policy. A and B argued that the CAS had violated the legal principles of non-retroactivity and of lex mitior (according to which the law most favourable to a perpetrator applies in cases where the legal situation has changed between the time the crime was committed and the punishment of the perpetrator).

The Federal Tribunal rejected the petition. It dismissed A and B's allegation that the CAS had violated the principles of non-retroactivity and of lex mitior. Accordingly, the Federal Tribunal, as it expressly stated, did not have to decide, whether these principles are effectively part of public policy in the sense of Article 190(2)(e) PILA, and if they are, whether they are part of substantive public policy or procedural public policy.

In the context of examining A and B's argument based on the principle of non-retroactivity, the Federal Tribunal highlighted that this principle does not normally apply to procedural rules, and held that procedural rules are subject to the principle tempus regit actum (according to which an act is governed by the law that is in effect when the act occurs).

In a recent decision rendered in a similar context, the Federal Tribunal had directly dealt with the merits of a public policy challenge based on non-retroactivity and lex mitior without questioning whether these principles are actually part of public policy in the sense of Article 190(2)(e) PILA. This could have been interpreted as an implicit presumption by the Federal Tribunal to this effect (see Legal update, Three decisions of the Swiss Federal Tribunal on sports arbitration matters). However, the Federal Tribunal's latest observations clarify that the Federal Tribunal continues to leave open the question whether or not the legal principles of non-retroactivity and lex mitior are part of public policy.