Northern Grampians Criminal Investigation Unit detectives are investigating after a large canola crop was destroyed in Glenorchy earlier this year.
Investigators have been told the crop, which is located near Old Glenorchy Rd, may have been poisoned in early or mid-June.
The value of the crop is estimated to be in the vicinity of $100,000.
Detectives are appealing for anyone who may have witnessed any suspicious activity in the area to come forward.
Investigators are also appealing for any other farmers who believe they have lost crops in suspicious circumstances to contact police.
Anyone with information or dash cam footage is urged to contact Crime Stoppers on 1800 333 000 or submit a confidential report online at www.crimestoppersvic.com.au