Despite the use of extensive resources, a fifth day of searching for a 76-year-old man missing in rugged bush in Tasmania’s northeast has not been able to locate him.

Peter Willoughby went missing on Sunday afternoon, about 2km from Hollybank, when he walked into heavy bushland and became separated from the people he was with.

Extensive police, ambulance and SES search and rescue resources have been deployed since Sunday to try and locate him.

Tasmania Police will not search the area on Friday due to safety concerns of officers working in heavily forested areas during a severe weather event.

Resources deployed earlier today involved specialist Tasmania Police Search and Rescue officers, Ambulance Tasmania paramedics and SES volunteers.

No helicopter or drone resources could be used due to inclement weather and low visibility.

Tasmania Police Northern District Search and Rescue Inspector Nick Clark said conditions were again very difficult, with search teams working in thick, rugged terrain through periods of rain, hail and extreme wind gusts.

Inspector Clark said teams scoured a new search area, to the south of the Hollybank reserve.

“Unfortunately, we have not been able to locate Mr Willoughby in today’s searching,” Inspector Clark said.

“We do, of course, hope that will be able to find Mr Willoughby, but as each day passes, there are grave concerns for his welfare.”

Mr Willoughby, pictured. was last seen wearing a dark blue jumper, blue jeans and sneakers.

Anyone who has information regarding the incident or who may have seen Mr Willoughby in the area from Sunday is asked to contact police on 131 444.