Colin Cramphorn: No information that IRA intends to resume violence

Sinn Fein's Martin McGuinness said people should be "highly sceptical" about claims of IRA involvement.

He said there was "no proof that the IRA was gathering intelligence about senior Tories".

Mr McGuinness said he was absolutely convinced that the IRA was not involved in the Castlereagh break-in.

The Conservative Party's Northern Ireland spokesman, Quentin Davies, was told of the find in a telephone call from Northern Ireland Secretary John Reid on Thursday night.

Mr Davies, whose name is not on the list, said it was a "deeply worrying state of affairs".

"Deeply worrying because it indicates, if it's true that the IRA are continuing to target people, preparing for military operations," he said.

The acting chief constable, Colin Cramphorn, said he had no information to suggest that the IRA intended to resume violence.

But he said an IRA link to the Castlereagh break-in was a major line of inquiry.

"I certainly had no information or indeed any other indication which would suggest to me that the IRA is either about to or is intending to recommence its campaign so if that is the point I have nothing to suggest that," he said.

David Ervine: "Huge implications for the peace process"

Northern Ireland Secretary John Reid said that the files did not prove that the IRA was about to resume its campaign.

"There is no indication that the IRA is either about to or intending to recommence its campaign," he said.

"We have always made it clear that all paramilitary groups must end all forms of terrorist activity - that includes collecting information."

Details

Security sources remain convinced that the IRA was behind the Castlereagh robbery in which sensitive Special Branch documents were stolen.

This was denied by the IRA leadership on 8 April, the same day that the republican paramilitary organisation announced it had carried out its second act of arms decommissioning under the Good Friday peace agreement.

John Reid: Told Tory NI spokesman by phone

David Ervine, of the loyalist Progressive Unionist Party, whose details were on the Special Branch documents, said the latest development had "huge implications for the peace process".

Deputy First Minister Mark Durkan said the discovery of the files proved the IRA was still active at a number of levels despite their ceasefire.

"Ongoing IRA activity has been a cause of continuing concern to many, just as the continuing actions of loyalist paramilitaries create anguish and fear," said the SDLP leader.

The Castlereagh raid was a huge embarrassment to the police service.

Special Branch deals with intelligence work, some relating to informers, and has an anti-terrorism role in Northern Ireland.

A Special Branch officer was assaulted when three men entered an office inside the east Belfast complex on 17 March.

As well as the high level police investigation, John Reid set up his own inquiry to establish the facts of what he described as a breach of national security.

Detectives on the investigation are understood to be interested in a number of mobile phones which were being used in west Belfast in the period leading up to the break-in and on the night of the robbery itself.

Movements

Those phones have not been used since then.

Calls to a number of public telephone boxes in west Belfast also form part of the investigation.

Police officers are checking the movements of a number of vehicles and people - including a prominent west Belfast republican - in the days before the break-in at Castlereagh, which houses the force headquarters for Belfast.

Intelligence assessments lead detectives to believe that the stolen Special Branch documents were moved from Belfast to Londonderry in the north west of the province and then across the border into the Republic of Ireland.