A chief superintendent police officer traveled from Belfast to the United States last week to question a suspect in the 1972 Claudy bombing who is being held by the FBI.
Nine people lost their lives in these bombings and 30 others were injured.
The Police Service of Northern Ireland (PSNI) had tried to gain access, through the High Court, to have a preview or to pull the broadcasting of a BBC documentary on the Claudy bombing. Mr Justice Treacy ruled against the police.
The police are concerned that witnesses or suspects will be named in the BBC “Spotlight” program.
The investigation in to the bombing of the small town in County Derry has been transferred from the Historical Enquiries Team (HET) to the serious crime branch of the PSNI.
Last August the Northern Ireland Police Ombudsman published findings that the RUC had colluded with the Catholic Church and the British government over the involvement of a priest, Father Chesney in the attack
The report stated that senior RUC officers sought the assistance of the Northern Ireland Office and the then northern secretary, William Whitelaw. He is turn spoke to the Catholic primate, Cardinal Conway, about their belief that Father Chesney was one of the Claudy bombers.
Father Chesney died in 1980 at the age of 40. He was never arrested or questioned was transferred, by Cardinal Conway, to County Donegal.
The families of the Claudy bombing victims are being kept informed of all developments in the case.