A passing driver saw a light aircraft ablaze in a paddock next to the Lyell Highway at Bronte Park about 3.30am today.

The plane was being stored at a property near the Marlborough Highway intersection, after dropping fertilizer nearby during the day.

Investigations have revealed that the fire appears to have been deliberately lit, and the incident is now being pursued by Bridgewater CIB.

Police wish to speak to anyone with any information about the fire.

Information can be passed on anonymously through Crime Stoppers on 1800 333 000.