A 10-year intelligence gathering operation against top businessmen in Northern Ireland was alleged by Democratic Unionist MLA Mr Ian Paisley Jr last night.
Mr Paisley said dossiers had been compiled on entrepreneurs and bundles of case notes, prepared by Northern Ireland Office staff, were among files allegedly stolen by Republicans at Stormont.
Mr Paisley said: "I have no doubt the IRA was spying, but what they managed to steal was ready-made NIO spy material.
"What has been uncovered is a nest of vipers not only on the Falls Road but also paid agents at the NIO.
"I would be naive not to think the Government is looking at politicians and people with dubious connections, but to be spying on ordinary citizens is like a police state."
Mr Paisley made his allegations yesterday as detectives warned him his details were found among more than 1,200 documents seized last year during raids. Officers visited a high-profile Northern Ireland businessman and a woman in north Antrim with DUP connections. Three planning applications linked to the party were listed on the papers, Mr Paisley said.
Four people, including Sinn Féin's administration chief and a messenger employed at former Northern Ireland secretary Mr John Reid's Belfast offices, have been charged in connection with the suspected spy ring.
An NIO spokesperson said: "There is an ongoing investigation into the activities which came to light on October 4th last year, and as such we would not want to comment." - (PA)