A community toilet block in Mooroopna was destroyed in a suspicious fire on September 29.
Police believe a number of young people were in the Elsie Jones Dve, Mooroopna, area before they entered the trotting track community area through a fence.
About 8.40pm, the group allegedly set items within the toilet block alight, causing the structure catch fire and burn completely, police said.
Police are investigating and have released a photo of the toilet block on fire, where you can see the silhouette of a person.
Anyone who witnessed the alleged incident or spoke with people in the area around that time are urged to contact Crime Stoppers on 1800 333 000 or submit a confidential report at www.crimestoppersvic.com.au