Police are investigating a fire at Old Noarlunga which caused extensive damage to a boat.

About 5.20am today, Friday 31 Octobe), police and fire crews were called to a house in Elizabeth Street after reports that a boat was on fire in the driveway.

MFS officers extinguished the blaze and there were no reports of any injuries.

The cause of the fire is undetermined, and anyone who may have witnessed the incident is asked to call Crime Stoppers on 1800 333 000, or online.