Ian Gray, 66, vanished on September 11 in 2015 after allegedly last being seen by a relative driving his white Holden Rodeo four-wheel drive out of his Bunnaloo Road property at Mathoura, south of Deniliquin.

Detective Chief Inspector Mick Stoltenberg said on Friday no trace of Mr Gray or his car had been found.

"None of his bank accounts have been utilised in that six-year period," he said. "Let's be realistic here, we're talking about something that stinks and he's got a family out there and they're really concerned."

Mr Gray's brothers Peter and Barry issued a joint statement via the police, saying they found it "amazing" there had been no sightings.

Nevertheless they said "we are encouraged by the police investigation and hope to be reunited with Ian soon".

Chief Inspector Stoltenberg said all possible avenues, whether personal or business-related, were being explored and any information would be welcome.

"We're not discounting anything ... we've got our eyes wide open," he said.

However, the Murray River police region crime manager was pessimistic when asked if Mr Gray would be found.

"I'm not confident, which is a terrible thing for the family, but again let's hope for a miracle," Chief Inspector Stoltenberg said.

Strike Force Kirkne was formed last November to re-investigate the disappearance of the sheep breeder.

A brief has not been presented to the coroner.

Anyone with information about Mr Gray is urged to contact Deniliquin police on (03) 5881 9299 or Crime Stoppers on 1800 333 000.