A BMW was set alight along McCallum Street on Monday night, with the owners and nearby neighbours waking up to a loud explosion.
The 1999 BMW sedan was well engulfed by the time firies arrived at 11.50pm.
The fire destroyed the car and police believe the offenders may have sustained burns while igniting the fire.
Swan Hill Crime Investigation Unit detectives have been told that three people fled the scene on foot, heading south along Murlong Street.
Investigators have released a photo of a baseball cap left at the scene and are keen to speak to any other witnesses or anyone that may have seen any suspicious activity in the area.
Anyone with information about the fire is urged to contact Crime Stoppers on 1800 333 000, or make a confidential report at www.crimestoppersvic.com.au.
