The Ulster Unionist Party has demanded that Policing Board vice-chairman Denis Bradley elaborate on his disclosure yesterday that in the early 1970s he used his influence to persuade the IRA to abort a plan to murder an RUC officer in Derry.
Mr Bradley also said that RUC Special Branch was prepared at the time to allow the IRA operation go ahead even though it knew one of its officers was being targeted.
Mr Bradley said he acted to prevent the killing at the request of the then RUC chief superintendent in Derry, Frank Lagan, who died after a long illness last week.
Mr Bradley made his surprise comment on BBC Radio Foyle yesterday which was recalling the career of Mr Lagan, who in 1972 warned of the potential for "intense violence" if the British army confronted demonstrators on Bloody Sunday.
Mr Bradley, who was a priest in Derry at the time, said he was contacted by Mr Lagan in the 1970s as the police officer feared RUC Special Branch was going to "sacrifice the officer". He told the programme he persuaded the IRA to call off the attack one hour before it was to happen.
"He [Mr Lagan] had got information that the Special Branch knew of an operation that the IRA were about to do and the Special Branch were going to let it go ahead even though it would have involved one of their own officers being killed.
"He asked me to go and stop it about an hour before it happened, if I could get in touch with somebody to stop it. He said to me: 'This is crazy if we let this kind of stuff go on'."
Ulster Unionist MLA Michael Copeland yesterday demanded "urgent clarification" of Mr Bradley's remarks.