The future of cross-border government enforcement investigations has been shaken by the U.S. Court of Appeals for the Second Circuit's recent decision in United States v. Allen, 864 F.3d 63 (2d Cir. 2017), which held that the Fifth Amendment's prohibition on the use of compelled testimony in criminal proceedings applies even when that testimony was compelled by a foreign official in a foreign investigation. Allen's ramifications are far-reaching and may put pressure on other circuits, including the Ninth, to embrace the holding or disavow it.

The Libor Investigation and 'Allen'

During late 2011 and 2012, the U.S. Department of Justice and numerous other government authorities, including the U.K.'s Financial Conduct Authority, were investigating the rigging of the London Interbank Offered Rate, in what became known as the Libor scandal. As a part of its investigation, the FCA obtained testimony from three British traders: Anthony Allen, Anthony Conti and Paul Robson. Their testimony was considered compelled because the traders faced criminal penalties under U.K. law if they had refused to testify. The FCA eventually brought an enforcement action against Robson, as part of which it disclosed the testimony of Allen and Conti.