A thermal drone and robotic camera failed to find signs of the man, who has been missing since 4am local time yesterday when a section of the mine collapsed.
Tasmania Police said overnight the search had used an additional drone with more sensitive three-dimensional laser technology as part of the operation to locate the missing mine worker.
"The amount of earth and rock and the situation that presents tells us that it is highly unlikely he could have survived," police said this morning.
"We will continue to work with the mine on the recovery operation which is likely to take some time but it's not possible to say how long."
According to the Australian Workers' Union, the best possible technology was being used in the search, with a charter plane carrying equipment provided by BHP flown into Queenstown last night.
Tasmanian premier Peter Gutwein expressed his deepest sympathy to the missing man's family.
"The Tasmanian government will continue to provide all necessary support and resources required to ensure the search operation at Henty gold mine can be conducted safely," he said.
"Our thoughts during this time remain with the worker's family and friends, co-workers, and the entire West Coast community."
The mine, owned by Diversified Minerals and operated by Pybar Mining Services, remains suspended.