Prosecutors in the U.S. are demanding that a university hands over to Britain taped interviews in which former IRA members purportedly accuse Gerry Adams of running a secret death squad.

Researchers on an oral history project for Boston College obtained the testimonies from two convicted IRA terrorists between 2001 and 2006.

Adams, president of Sinn Fein, has always denied being an IRA member, let alone heading a unit which – in kidnapping, torturing and killing suspected informants – carried out some of its most brutal acts....