Police are appealing for witnesses to a grassfire in Bunkers Hill last month.
The grassfire which started in nearby Haddon on Friday March 29 spread over 150 hectares in a south-easterly direction towards the Glenelg Highway.
The fire is being investigated by detectives from Ballarat Crime Investigation Unit, in conjunction with the Arson and Explosives Squad with assistance from other government agencies.
There are a further two fires in nearby Mount Mercer and Learmonth which are not being treated as suspicious and are not linked to the fire in Bunkers Hill.
Locals in the area have been advised to remain vigilant.
Investigators are urging anyone who may have relevant dash cam vision, photographs or video footage of the early stages of the bushfire, or has any information that may assist the investigation to contact Crime Stoppers on 1800 333 000 or submit a confidential crime report at www.crimestoppersvic.com.au