Provincial police have launched a criminal investigation into the conduct of some Ontario government employees in deals with private companies.

Officers are looking into possible ''irregular transactions'' between government ministries and "outside vendors."

Ron McKerlie, deputy minister for the Ministry of Government Services, said in a release that staff are co-operating with the Ontario Provincial Police.

According to unidentified sources quoted by the Toronto Star, OPP officers executed search warrants at a government building near Queen's Park on Thursday. The building houses offices for many government departments, including the Ministry of Health, the Ministry of Energy and Infrastructure, and Ontario Realty Corp.

ORC manages one of the largest real estate portfolios in Canada, including 6,400 buildings and more than 40,00 hectares of land.