A car found burned out with false number plates identical to those owned by a police officer could be linked to the mystery raid of Northern Ireland Special Branch files in Castlereagh, it emerged tonight.
The wreckage was discovered near Carryduff, Co Down, on the outskirts of Belfast in the hours following the burglary, security sources revealed.
As well as the registration, the car was also of the same make and colour as the one owned by the officer.
Documents, notebooks and papers were seized in the break-in seven weeks ago which led to the British government to order its own investigation.
Security sources said IRA involvement in the theft of hundreds of telephone numbers of Special Branch officers and informants' codenames was still the main line of inquiry. But they also claimed nothing had been ruled out. All sides, including their own agencies, remained under investigation, they said.
One declared: "All bets are still on."
A definite connection between the "ringer" car and the burglary on St Patrick's Night has not been formally established, but sources confirmed it was under investigation.
One claimed the officer was based at Castlereagh, but others said he operated out of another station in the greater Belfast area. He is not under suspicion, sources said.
The burned out car was found on March 19th.
A spokesman for the Police Service of Northern Ireland said he was not prepared to comment on their probe.
But if it turns out the car was used, then it reveals a new insight into the sort of detailed planning which went on in advance of the raid when three intruders, one with an English accent, managed to get into Castlereagh and overpower an officer before rifling desks and cabinets.
A number of republicans in Belfast and Derry were questioned about the theft, but none has been charged and none of the missing files have been recovered.
The IRA and Sinn Féin leaderships have categorically denied any republican involvement.
Sir John Chilcot, a former permanent secretary at the Northern Ireland Office, is heading a government review to establish how the break-in happened, and assess the extent of any damage to national security.
His report will go to the Northern Ireland Secretary of State Dr John Reid, but given the sensitivity of the inquiry, it is unlikely to be published in full.
A chef who worked at Castlereagh at the time of the raid has been interviewed twice in New York by detectives from Belfast, but sources said there are no plans to have him returned to Northern Ireland to face further questioning.
The man, a Polish-American known as Larry the Chef, not only prepared meals at the police centre, but was also hired for private functions attended by officers belonging to Special Branch and British military intelligence.
Sinn Féin president Mr Adams insisted tonight that the party was standing by its position that republicans had nothing to do with the Castlereagh break-in.
He said the story was likely to have "more twists that Chubby Checker" and it was becoming ridiculous that republicans had to respond to "each and every new revelation or spin".
Speaking in Tralee while campaigning for Sinn Féin in the Election, he said: "We are sticking by our original position, one which is shared I think, by the vast majority of people including unionists, which is that it was an inside job."
PA