A detective heading the Claudy bombing investigation has travelled to the US to question a suspect detained by the FBI.
The detail emerged yesterday as the PSNI failed in a legal bid to view BBC NI's Spotlight documentary into the bombing before it was broadcast last night.
According to the BBC lawyers for the chief constable sought a last-minute High Court injunction to try to view the programme.
If that was not permitted, they wanted to stop it from being broadcast.
Nine people were killed in the attacks in 1972 believed to have been carried out by the IRA, but no-one has ever been convicted over it.
One concern of the police was that suspects or witnesses in the investigation could be named in the documentary.
The fact that a detective had questioned a man in the US was revealed in court.