Police investigating the death of prospector Raymond Kehlet and the disappearance of his wife, near the remote town of Sandstone are about to conduct another search of the area, their fifth in the past seven months.

The couple, from Beverley, disappeared in March while prospecting near Table Top, 730 kilometres north-east of Perth.

The body of 47-year-old Ray Kehlet was later found in a mine shaft.

His 49-year-old wife, Jennie, is still missing.

Superintendent Alan Morton from the Major Crime Squad said police wanted to hear from anyone who may have seen a vehicle of interest.

"A four-wheel-drive, towing a trailer with a quad bike on the back of it, in the early hours of the morning of March 22nd this year, south of the Table Top camp site on the Sandstone Payne Find Road," he said.

He said from Monday a team of 10 officers would scour sites south of the Kehlet's camp site, near the Paynes Find-Sandstone Road.

Superintendent Morton said ongoing investigations had identified those areas of particular interest, and urged anyone who may have visited the area since the Kehlet's disappeared to contact police.

"The Sandstone area is visited by travellers and prospectors, including many who may have been out of range for significant periods of time, or indeed may have since travelled interstate," he said.

"We are keen to hear from anyone who was in this area in mid to late March, who has seen the four-wheel-drive which was towing the quad bike, or has information regarding this tragedy to come forward."