An experienced Ottawa police officer is the subject of a criminal investigation involving what police are calling a "hit-and-run" on St. Patrick's Day, CTV Ottawa has learned.

Sources tell CTV Ottawa the off-duty police sergeant was at a bar with friends on March 17.

A criminal investigation started a few hours later when the police officer's personal vehicle was involved in a single-vehicle crash.

Sources say the officer reported the vehicle stolen after the crash, and a bartender has already been interviewed.

Supt. Mike Flanagan would not comment on that. However, he did tell CTV Ottawa that police Chief Vern White is taking the investigation seriously.

"If there is a need to let the public know that one of our members may or may not be involved, we will be very transparent. If it's a good day for the officer, it's a good day. If it's a bad day, it's a bad day for that officer," said Flanagan.

While the criminal investigation is ongoing, Flanagan said the officer will likely be charged as a result of a professional standards investigation.

"Charges are likely under the Police Services Act, regardless," Flanagan told CTV Ottawa.

He said investigators have not yet determined who was behind the wheel at the time of the crash.

"What is crucial to any investigation, especially a hit-and-run is to determine who the driver is. That determination has not yet been determined. The officers are still interviewing witnesses in the process of the investigation."

Flanagan said he expects the criminal investigation to be wrapped up within one week.

The officer in question is currently working and on patrol. He has not been named because he hasn't been charged with a crime, which is standard practice for any police investigation.

With a report from CTV Ottawa's Kimothy Walker