TORONTO -- The Ontario Provincial Police have launched a criminal probe into the destruction of emails about the cancellation of two gas plants by senior Liberal staff.

The province's privacy watchdog issued a scathing report this week saying they broke the law by deleting emails on cancelled gas plants in Oakville and Mississauga.

OPP Commissioner Chris Lewis says he's referred the matter to the Criminal Investigation Services and will interview people named in the report.

He says it's hard to say how long it may take before police determine whether any criminal charges should be laid.

The privacy commissioner reported that former premier Dalton McGuinty's chief of staff, David Livingston, tried as late as January to find out how to permanently delete emails related to the gas plants.

The opposition parties say the emails were wiped out by the Liberals to try to cover up the true costs of cancelling the gas plants.

The price tag has grown to an estimated $585 million, well above the $230 million the government had claimed.