The Secretary of State for the North has been called on to make a public statement over the removal of 28 soldiers from duty following a suspected security breach at Castlereagh.
Sinn Féin Assembly member Gerry Kelly issued the call to Mr Paul Murphy as republicans staged a protest beneath an Army observation post in west Belfast where some of the soldiers were reported to have worked.
The army confirmed on Wednesday that 28 Royal Irish Regiment (RIR) troops had been transferred to alternative duties during a police investigation into the disappearance of a sensitive document from the Castlereagh security complex in east Belfast.
North Belfast MLA Gerry Kelly
Security sources have indicated that the army's Special Investigations Branch has interviewed the soldiers and at least eight of the troops are to face further questioning.
It is thought the details of around 400 people are contained in the document and Sinn Féin has asked the Minister for Foreign Affairs, Mr Cowen, to raise the matter at the highest level with the British Government.
During today's protest outside Divis Tower, North Belfast MLA Gerry Kelly said it was untenable for the British to maintain silence on the security breach.
"There is a real fear that the events unfolding in Castlereagh and at Divis Tower spy post are another chapter in the collusion scandal," he said.
"We have a dossier missing from Castlereagh and the potential for intelligence gathering on the nationalist community from Divis Tower is very obvious.
"Paul Murphy is now back in Ireland and I am demanding that he makes a statement on this scandal," Mr Kelly said.
He added it was essential that all those listed in the document were informed of the possible threat to their safety.
Given previous allegations of collusion between the security forces and loyalist terror groups, he said nationalists had no faith in a Police Service of Northern Ireland assessment that people's lives are not at risk.