Police are investigating a suspicious fire at Mount Gambier.

Just before 5pm on Sunday 23 August, police and fire crews attended at the corner of Radiata Street and Pick Avenue after reports of a building fire.

When police arrived, they found a large fire at a disused factory. Fire crews brought the blaze under control which completely destroyed the structure.

Initial investigations indicate that the fire was deliberately lit.

Fire Cause Investigators will be travelling to the scene from Adelaide tomorrow to determine the cause of the fire.

Anyone with information is asked to contact Crime Stoppers on 1800 333 000.