Mr Wills reportedly had sheep stolen from his property not long before his killing. Picture: supplied

A new theory has emerged after a northern Victorian farmer was found shot dead in a shallow grave on his property.

The body of Richard Wills was found on his rural property on Tuesday, more than two days after he was reported missing.

As investigations continue, police have said they are “mindful” of theories suggesting the killing of the 65-year-old farmer had anything to do with reports of stolen livestock in the region.

Ouyen has a population of just over 1100 people. Picture: Google

It has been reported by numerous outlets that Mr Wills reported a number of sheep stolen from his property in Ouyen, Victoria, shortly before he was killed.

Detective Senior Sergeant Steve Trewavas from the Victoria Police Missing Persons Squad told reporters on Saturday that investigators were keeping their minds open.

“It is something that we are mindful of in relation to this investigation,” he said.

Mr Wills was last seen leaving his Hughs St home in the small Victorian town of Ouyen about 8am on Easter Sunday but failed to return home for lunch.

Police were told Mr Wills had gone to work on his rural property on the Mallee Highway, which was his normal routine.

He was reported missing the following day.

His body was found buried in a shallow grave during an assisted search of the rural property about 1.30pm on Tuesday.

Richard Wills, 65, was last seen alive on Easter morning. Supplied: Victoria Police

The 65-year-old was fatally shot, with Victoria Police missing persons detective senior sergeant Steve Trewavas saying Mr Wills’ death was clearly “foul play”.

“Sadly, Richard has clearly met with foul play,” he said.

“What is still unclear is exactly who was involved, and why.

“We are very keen to speak to anyone who may have any knowledge of the circumstances which led to his death and who was responsible.

“We’re hoping that this appeal leads to someone coming forward and doing the right thing – it can be done anonymously – so that we can hold those responsible to account.”

Wills’ body was found in a shallow grave on his rural Ouyen property in northeast Victoria. Picture: Google

Mr Wills’ wife, Donna, says they have “lots of grandkids that are going to miss him” while speaking at a press conference on Saturday, according to the Herald Sun.

“If he saw someone stopped on the side of the road he’d be the one who would turn around, go back, and make sure they were alright,” she said, according to the outlet.

Anyone who saw Richard on Easter Sunday or who may have any information regarding his death is urged to contact Crime Stoppers on 1800 333 000.