James Hugh McLean, from Flinders Island, started a month-long bushwalk on November 13. 

The 76-year-old was planning to walk to Melaleuca via the Huon Track near Tahune, before returning on December 13.

Tasmania Police said Mr McLean did not reach his food drop at Melaleuca and has not returned home. 

“He is a reasonably experienced walker who has completed walks in this area before,” police said. 

The search continued on Wednesday using the Westpac Rescue Helicopter. 

Acting Inspector Andrew O’Dwyer said more than 100 kilometres of walking tracks leading in and out of the area had been covered by both air and on the ground during the week-long search.

“Sadly, police hold grave fears for Mr McLean. Given the length of time he has been missing, the lack of food supplies and the difficulty of the terrain, the hopes of finding Mr McLean alive are fading,” Acting Inspector O’Dwyer said.

“We remain in close contact with Mr McLean’s family and our thoughts continue to be with them at this difficult time.”

Police are calling for assistance from the public and ask anybody who came across Mr McLean during the walk or has since seen him to contact police on 131 444.