Unionist paramilitaries are believed to have been handed a British Army dossier on leading republicans following an incident at the top security Castlereagh base in east Belfast.
The UDA is reported to be in possession of the list, which was ‘stolen’ from Castlereagh in recent weeks.
It has emerged that a British soldier took military documents from the interrogation centre earlier this summer.
Nationalist politicians have demanded an urgent meeting to discuss the latest incident.
Amid signs of media management and damage limitation, British security minister Ian Pearson has only confirmed that a document is missing.
The PSNI police said last night it would be improper to comment about the matter, as it was currently under investigation.
The regiment involved is understood to be the RIR, a regiment with a long history of collusion with unionist paramilitaries.
It was at the same complex in March 2002 that a previous ‘break-in’ took place. After initially blaming Crown force insiders for taking sensitive documents, the PSNI police subsequently blamed the IRA.
The allegations were firmly denied by republicans, but caused upheaval for the peace process. No-one was ever charged over the affair.
Sinn Féin’s Gerry Kelly has demanded answers about the incident.
“If people’s details are missing from Castlereagh the very least that the British government need to do is to inform those people without any further delay,” said Mr Kelly.
“It is a disgrace that the British government have been sitting on this information for some weeks therefore putting people’s lives in danger.”