Hamilton police are hunting an arsonist who set fire to a $42,000 police car on Sunday.

A video of the fire uploaded to YouTube on the same night is also being investigated.

The car was one of four parked at the Hamilton East community police station in Clyde St when it was set alight about 8pm.

Police said the fire caused extensive damage to the car and was being treated as suspicious.

Night shift manager Acting Senior Sergeant Neville Ross said emergency services arrived at the unmanned station at 8.15pm to find the car well ablaze.

"A window of the car had been smashed and a fire started."

One witness said the vehicle was completely burnt out and the fire had the potential to spread to the other patrol cars and the station were it not for firefighters who quickly brought it under control.

Police spokesman Andrew McAlley said police were investigating reports of a white car seen near the station car park around the time the fire started.

He said any witnesses, including those who took cellphone video footage of the fire, should call the Hamilton Central police station on (07) 858-6200.