Warrnambool police Sergeant Chis Moloney said the man owned a ​farm at Hawks Nest Road, Pomborneit East.

At 2.50pm the man left to bring in cows for milking. At 7.30pm another man arrived at the property to find the cows had not been milked.

He found the deceased man in a back paddock with the quad bike on top of him about 8.30pm and called emergency services. 

Sergeant Moloney said the area where the accident happened involved a steep rocky incline and the bike appeared to have flipped back on the farmer.

Warrnambool police crime investigation unit detectives will prepare a report for the coroner and Worksafe is also investigating.

Worksafe Victoria said it there had been nine workplace deaths involving a quad bike in the past six years. Five of those accidents occurred in the south-west.   

Australian Centre for Agricultural Health and Safety data shows 15 people were killed across Australia using quad bikes in 2015. More than 220 people have been killed while riding quad bikes since 2001.

In March, WorkSafe announced it was reviewing rules around quad bike use, requiring rollover protection to be fitted. The regulation will come into force within 18 months.

“This is a tragic reminder to all farmers to think about safety every day,” Worksafe spokeswoman Caitlin Rode said. 

“The shocking fact is that farmers are far more likely to die at work than any other Victorian worker.”