Several Northern Ireland civil servants are under investigation as part of a major inquiry into the awarding of military contracts worth millions of pounds.
With up to 170 Ministry of Defence serious fraud officers from Britain involved in a series of searches in Belfast and other areas yesterday, a number of people linked to private-sector building firms are also being probed.
Computers and documents were removed for examination.
The inquiry stretches back to the awarding of contracts in the late 1990s. Fifty police officers also took part in yesterday's operation. Offices and commercial premises were searched in Belfast, Lisburn, Newtownabbey and Antrim.