Former Victoria Police chief commissioner Christine Nixon has been caught driving an unregistered car during a traffic operation on the Mornington Peninsula.

Ms Nixon, of Blairgowrie, told radio station 3AW that she was driving her new car on the Mornington Peninsula Freeway in Rosebud about midday on Tuesday when she was stopped by police for driving an unregistered vehicle.

Ms Nixon said the unpaid registration was an oversight, and that she paid it before moving her car off the freeway.

She is expected to receive a $722 fine in the mail for driving an unregistered vehicle.

Ms Nixon praised police for their handling of the situation.

Ms Nixon quit her chief commissioner post in November 2008, when she announced she would not renew her contract the following year.

She was sworn in as Victoria’s 19th chief commissioner in April 2001, and was the first woman to be in charge of an Australian police force.

Ms Nixon said that despite offers from the government – led by then-Premier John Brumby – to continue, she believed it was time to go after nearly eight years in the top job and 36 years as a police officer.

The former police chief also chaired Victoria’s Bushfire Recovery and Reconstruction Authority after the devastating Black Saturday bushfires.

In 2010, Ms Nixon announced she would be stepping down as the head of the bushfire reconstruction authority.

The former top cop was heavily criticised for her decision to go the pub with friends on Black Saturday when she was still the state’s police chief.