TORONTO Ontario's police chief confirmed Thursday that hard drives from government computers were seized as part of a search of an unnamed data storage facility in Mississauga last week.

The search was part of the criminal investigation into the deletion of emails on two cancelled gas plants in Oakville and Mississauga.

OPP Commissioner Chris Lewis didn't say what was found on the hard drives or what evidence led police to the facility, telling a legislative committee that he has deliberately stayed out of the ongoing investigation so it won't be compromised in any way.

A "handful" of investigators involved in the probe of the deleted emails have interviewed about 20 officials, he said.

But he couldn't say whether a criminal act occurred, whether any charges will be laid, or even when the investigation may end.

Investigators also visited Premier Kathleen Wynne's office last November as a "familiarization" exercise, possibly for a few hours, he told the committee. There was no search warrant and the officers had the full co-operation of her staff.

"It wasn't a search," he said following his appearance.

"So they weren't crawling around looking under desks and going through closets. They wanted to see the layout of the office area. That was it."

Police launched a criminal probe last June after the Progressive Conservatives complained that gas plant emails were intentionally deleted by senior staff in former premier Dalton McGuinty's office.