Premier Kathleen Wynne, who was not going to be on hand when the OPP tour her office at the legislature, said she will co-operate with the police investigation.
"All I can say is that this is an investigation that was requested by the Opposition," Wynne said at an event in Waterloo. "I've said from the time that I came into this office that as there were questions about the issues around the relocation of the gas plants that we would provide that information. We will continue to do that."
The Official Opposition called it a sad day when police visit a premier's office.
"The police are going to treat the premier's office as the scene of a crime, and this is virtually unheard of," said Progressive Conservative energy critic Lisa MacLeod. "It's an extremely sad day for democracy in this province when Premier Wynne is going to have to entertain the OPP in a police search of her office."
Police launched a criminal probe last June after the Conservatives complained that emails on the gas plants were intentionally deleted by senior staff in former premier Dalton McGuinty's office.
The New Democrats said Wynne was in the McGuinty cabinet at the time and was part of the team that approved the gas plant cancellations to try and save Liberal seats in the 2011 election, and should be part of the OPP probe.
"Senior Liberal insiders were deleting public records and to me that looks like a coverup of the gas plants affair," said NDP energy critic Peter Tabuns. "I'm glad the OPP are taking it seriously and are investigating."
Ontario Privacy Commissioner Ann Cavoukian found last June that top Liberals in McGuinty's office broke the law when they deleted emails on the cancelled gas plants in Oakville and Mississauga prior to the 2011 election.
The opposition parties said the emails were wiped out to cover up the true costs of killing the gas plants, which the auditor general has estimated are as high as $1.1 billion, a theory the privacy commissioner agreed was likely.
"It is difficult to accept that the routine deletion of emails was not in fact an attempt by staff ... to avoid transparency and accountability," Cavoukian reported.
McGuinty insisted last summer that he never condoned or directed the deletion of emails or documents which should have been preserved under law.
It was the government's initial refusal to release gas plant documents that led to a rare and often nasty contempt of Parliament debate, which prompted McGuinty to prorogue the legislature for four months and resign as premier.
The government eventually turned over more than 186,000 documents and emails related to the gas plants, but in several batches, and insisting after each one that all the relevant correspondence had been released.
The OPP did not immediately respond Wednesday to calls requesting comment on the investigation of the premier's office.
The Liberals released a new television ad Wednesday featuring Wynne, an avid runner, jogging along a rain-swept rural road.
The Tories couldn't resist linking the video to the police visit to Wynne's office.
"It looks like she's running away from the OPP," quipped MacLeod.