Renewed search for missing hiker fails to find clues

A fresh search of southern Tasmanian bushland has failed to find any trace of a 66-year-old man who was reported missing from the area six years ago.

Police last month revealed their investigation into the disappearance of avid hiker Bruce Fairfax was now being treated as a criminal matter.

Mr Fairfax was reported missing by his wife on October 14, 2017 after the pair became separated while on a walk with their dog in the Duckhole Lake area.

About 90 search crew, including police and members of walking clubs, began a fresh two-day search of the area on Thursday morning.

"Nothing relevant to the investigation has been found at this stage," Tasmania Police said in a statement on Friday afternoon.

Police have re-interviewed witnesses as part of the criminal probe and have indicated they are keeping an open mind to all possibilities, including that Mr Fairfax was never at the lake.

They are urging anyone with information to come forward.

The original search for Mr Fairfax, which involved about 60 people including the former teacher's students and family, was called off after about a week.

Mr Fairfax, who required daily medication for Parkinson's disease, was described by his wife as a "gentle, patient, generous giant".

Duckhole Lake in Tasmania's Southwest National Park is a flooded sinkhole and part of an extensive regional cave system.