Queensland police are searching a rubbish dump for the remains of a missing diamond miner who vanished a month ago.

A search is underway at a Queensland landfill site for the remains of a diamond miner who vanished a month ago.

David Hanson, 71, was supposed to catch a flight to Tanzania on February 22 but never made it to the airport.

Police believe his body and belongings were dumped in a bin south of Brisbane and on Saturday began searching garbage at a waste transfer station.

Fifty-two State Emergency Service volunteers began sifting through 5000 tonnes of compacted waste at the Browns Plains Waste and Recycling Facility using rakes and garden forks on Saturday.

Police won’t speculate on a motive.

They say Mr Hanson was jailed for drug trafficking in the United States two decades ago and was not a particularly wealthy man.

Detective Superintendent David Hutchinson said police had set aside a month for the search, which would be a slow and methodical process.

“There’s been no proof of life in relation to Mr Hanson since the 22nd of February,” he said.

“We always hope for the best and we hope that there’s been a reason why he’s gone away … but the evidence that we have would suggest otherwise.”