A Shepparton council facility was broken into three times last week.
Police said it was understood an unknown man gained access to a Greater Shepparton City Council depot on Doyles Rd about 11.30pm on Monday, December 4.
The same man attended the business again just before midnight on Wednesday, December 6 and about 3.30am on Thursday, December 7.
Police believe the man stole a trailer on each occasion, as well as a large orange generator.
It is understood the man fled in a white Isuzu D-MAX ute bearing stolen registration plates, police said.
The ute is described as having a black bull bar, silver flat tray, broken right rear tail light and broken right headlight.
Police are appealing for public help to locate the man.
Investigators have released CCTV footage and images of a man they believe may be able to assist with their enquiries.
The man is believed to be Caucasian in appearance, between 30 and 40 years old, with a medium build.
He was wearing a yellow high-visibility shirt with khaki pants, work boots and a black face covering.
Anyone with information or CCTV footage is urged to contact Crime Stoppers on 1800 333 000 or make a report online at www.crimestoppersvic.com.au