An investigation into the Omagh bombing has been left “clouded in secrecy” after the Prime Minister repeatedly blocked access to secret documents, MPs claimed today.

Key findings about claims that vital information picked up from bombers' phone calls was not passed on to RUC detectives in the days after the attack have been withheld from the North-ern Ireland Affairs committee.

Its members are holding an inquiry into the atrocity, but today have taken the step of publishing a report solely criticising the Government for turning down its requests to see a confidential briefing on the claims.

Asked if failure to release the findings left the inquiry clouded in secrecy, chairman Sir Patrick Cormack replied: “It has.”

“We don't feel this is satisfactory. Quite a few people have already read it, including senior civil servants and members of the PSNI,” he said.

“We are in the dark. We just feel that for the sake of completeness we should be able to say we have seen this report.”

Gordon Brown last year ordered Sir Peter Gibson to examine claims in a Panorama documentary that GCHQ was monitoring calls made by the bombers in the run-up to the 1998 Real IRA blast that killed 29 people in Co Tyrone.

Relatives, unhappy with the findings, called on the Northern Ireland Affairs committee to step in to investigate and are pushing for a full public inquiry.

But only the summary of Sir Peter's report was given to the committee. As the full document contains sensitive information about security forces, Sir Patrick was charged with viewing it alone on behalf of the committee, but was refused by Government.

He submitted three requests to Downing Street, as well as bids to Secretary of State Shaun Woodward and Cabinet Office Minister Tessa Jowell, which were all turned down. In a letter, the Prime Minister said: “The published version of Sir Peter's report omits only the extensive, sensitive detail of Agency sources, methods and capabilities which must continue to be protected from unnecessary disclosure for national security considerations.

“I have previously assured you that Sir Peter's full report is entirely consistent with the full classified version and you now have Sir Peter's categorical assurance to that effect as well.

“You also have Sir Peter's unequivocal assurance that the Omagh bombing could not have been prevented by the better use of any intelligence that might have existed, and there is nothing in the full report which supports the concern among the Omagh families about whether those who carried out the bombing could have been identified and arrested in the aftermath.”

But in its special report, The Omagh Bombing: Access To Intelligence, the committee cites Government guidelines that allow it to provide information on a confidential basis, if it is impossible to do so publicly.

Report ‘helps in bid for public inquiry’

A damning report critical of the Government’s refusal to reveal secret documents about the Omagh bomb investigation strengthens a case for a public inquiry into the atrocity, the campaign group for relatives of the victims has said.

Michael Gallagher, whose son Aiden died in the 1998 Real IRA bombing, made the comments after members of the Northern Ireland Affairs committee published the report.

It was issued after the Government repeatedly blocked requests made by Chairman Sir Patrick Cormack to see a confidential briefing on the claims that vital information picked up from bombers’ phone calls was not passed on to RUC detectives in the days after the attack.

Mr Gallagher, who is chair of the Omagh Support and Self Help Group, said: “We believed it was vital to establish what happened in the days prior to and on the day of the bombing. And sadly that is not going to happen and it is inevitable that people will draw their own conclusions,” he said.

He added: “I think reports such as this one coming out strengthen our call even further that there should be a public inquiry, because obviously our Government wants to hide information from the families. That in itself is very damning on the Government’s part.”