Peter Hain warned his computer 'may have been hacked'
The former Northern Ireland Secretary, Peter Hain, is understood to have been warned by police that his computer may have been hacked.
According to the Guardian newspaper, it is thought that any hacking may have been carried out by private detectives working for News International.
Computers belonging to other senior Northern Ireland civil servants may also have been compromised.
A spokesman for Mr Hain said the matter is a "matter of national security".
Mr Hain was Secretary of State for Northern Ireland from 2005 to 2007, was involved in peace negotiations and as a result would have had access to sensitive security data.
He has declined to discuss the hacking claims, but a spokesman said: "This is a matter of national security and subject to a police investigation so it would not be appropriate to comment."
The investigation is part of Operation Tuleta, which is looking into privacy intrusions not involving phone-hacking.
Tuleta was launched over the summer after a "scoping exercise" into allegations surrounding the use of private detectives.
Officers working on the inquiry have been reporting to Deputy Assistant Commissioner Sue Akers, who heads the inquiry into mobile phone interceptions at the News of the World.
Police have already made a number of arrests in the phone-hacking investigation.
News International has said it is co-operating fully with the police on all investigations, while Scotland Yard says it would not provide a "running commentary" on the investigation.