POLICE are investigating the cause of a fire that destroyed a shed containing used mattresses.
Fire crews were called to the scene of a blaze at the Creswick Transfer Station on Ring Road at 1am on Friday.
Crews battled the blaze for 20 minutes which melted sections of the shed and destroyed mattresses and furniture being contained.
A crew from Ballarat City was en route before it was told it wasn't needed.
Two trucks from Creswick and one each from Newlyn and Kingston attended.
The fire is being treated as suspicious.
Police said there is no obvious sign of broken entry.
Moorabool Crime Investigation Unit detectives and a CFA fire investigator were at the scene at midday on Friday.
Police are appealing for any witnesses to the incident to contact Bacchus Marsh Police station on 5366 4500 or Crime Stoppers on 1800 333 000.