TORONTO - At least two Ontario government ministries are the subject of a criminal investigation into "irregular financial transactions" involving outside vendors, a senior government source said Saturday.

Officers from the Ontario Provincial Police raided several ministries Thursday as part of their probe into these activities, but a senior government source said the investigation did not involve elected officials.

"No politician or political staff is involved," said the government source who had been briefed on the investigation, and who also believed police were looking into more than one ministry.

OPP media officials have said the force's anti-racket branch is conducting the investigation.

Supt. Angie Howe, in charge of corporate communications for the provincial police, said search warrants were executed on Thursday.

"The OPP received information that led to an investigation into irregular financial transactions between government ministries and vendors," said Howe.

Howe said officials only started investigating on Thursday, and need some time to examine criminal allegations, which the police won't divulge.

"As soon as we know the scope ourselves, and we have further information, we'll certainly be willing to speak to it," said Howe, who added police may release what specific ministries are involved early next week.

The raid took place around a group of government buildings known as the Macdonald Block in downtown Toronto.

The Macdonald Block is a large complex located near the legislature which encompasses four different government buildings and 13 different ministries, including the offices of senior bureaucrats and ministers.

The ministries include Health and Long-Term Care, Energy and Infrastructure, Education, Consumer Services, Training, Colleges and Universities, Tourism and Culture, Government Services, Economic Development and Trade, Transportation, Environment, Research and Innovation, Northern Development and Mines and Community and Social Services.

The Ontario Realty Corporation also has its offices in the complex.

The government said it is fully co-operating with the provincial police.

In a statement, Ron McKerlie, Ontario's deputy minister of government services, said he understands the investigation involves individuals working in the government.

"We take these matters very seriously. Staff are fully co-operating - and will continue to co-operate with the police," McKerlie said.

McKerlie added that the Ontario Public Service is deeply committed to upholding the public trust, and providing high-quality services to the people of Ontario.

In a telephone interview Saturday, Craig Sumi from the Ministry of Government Services said officials would act swiftly if an investigation unveils illegal activity.

"If there was any wrongdoing, there will be consequences for the individuals involved," Sumi said.