Ulster Unionist Party leader Mr David Trimble has called for a full judicial inquiry into the events surrounding the 1972 Claudy bombing.
He was speaking after police said the British government and the Catholic Church tried to cover-up the involvement of a priest in the attack which left nine people dead in the Co Derry village.
The IRA has always been suspected of carrying out the bombing, but has consistently denied it.
Mr Trimble said: "This is extremely serious, and we expect the police will now follow this up in terms of what they do and their inquiries.
"Isn't it ironic we have been hearing over the last weeks and months the public inquiry into the deaths of innocent people on Bloody Sunday, which it has been suggested that there was some sort of official cover-up in terms of what happened, and there isn't?
"Now we're in a situation where it has been suggested there has been a cover-up of the murder of innocent people in Claudy and I would hope that issue is pursued and inquired into with the same vigour and with the same public result as the Bloody Sunday inquiry."