Ontario Provincial Police have been called in to investigate ORNGE, the province's troubled air ambulance service.

"The OPP is conducting an investigation into possible criminal activities on the part of ORNGE air ambulance service," police spokeswoman Cathy Bell said Thursday.

The police probe was launched at the request of the Ministry of Health and Long-Term Care, she added.

A source said the ministry asked police to look into "financial irregularities" at ORNGE on the advice of forensic auditors who were examining the agency's books.

The police probe is being led by the Criminal Investigation branch, which takes on major cases, Bell said.

The criminal investigation is the latest blow to ORNGE, which receives about $150 million a year from the province to operate a non-profit air medical rescue and transport service.

It's been under a cloud of controversy for months over high salaries, questionable spending and business practices.

There were reports in recent days that the agency loaned its former chief executive officer Chris Mazza $1.2 million over the last two years, on top of his generous salary.

Province cleaned house at agency last month

Health Minister Deb Matthews cleaned house at the agency last month, replacing Mazza — who was paid $1.4 million a year — and the entire board of directors. ORNGE was also ordered to shut down its for-profit companies.

The agency said no severance payments were offered to Renzella and Mazza, who was paid more by Ontario taxpayers than any other public sector worker last year.

The clean sweep came after the auditor general and the Ministry of Finance sent in forensic auditors to take a look at ORNGE's books.

Ian Delaney, chairman of Sherritt International Corp., was appointed as chairman of the new ORNGE board on the recommendation of the governing Liberals.

Other new members include former Progressive Conservative attorney general Charles Harnick of Counsel Public Affairs, Patricia Lang, former president of Confederation College and Sunnybrook Health Sciences Centre CEO and president Barry McLellan.

The new board was appointed Jan. 25, just a day after Ornge axed 18 middle managers and shut down its charity organization, J-Smarts, which educates children about cottage country safety, in a bid to reduce costs.

The ministry's emergency health services branch is also investigating 13 incidents related to air ambulance transports, three of which involved deaths of patients.