Stawell police Sergeant Bill Alford said a four day search involving up to 50 people each day had not uncovered any leads to his whereabouts.

“We covered a lot of ground,” Sergeant Alford said.

He said the dog squad, air wing unit, all-terrain vehicles and motorcycles had all been utilised in the search.

Sergeant Alford described the terrain near Mr VanDerWerf’s vehicle as “rugged”.

“There are walking tracks through it which we well and truly canvassed,” he said.

“The terrain is enveloped in undergrowth and quite steep.”

Sergeant Alford said there was a lack of mobile phone reception in the area and encouraged bushwalkers to invest in a satellite phone or EPIRB device.

“Anyone who wishes to bushwalk or camp in the Grampians need to be aware of the surroundings and be prepared,” he said.

Despite the lack of mobile phone coverage, Sergeant Alford said it was important bushwalkers ensured their phone was fully charged.

Sergeant Alford also urged people to let someone know where they were going.

He encouraged bushwalkers to travel in pairs.

“It’s better to have someone with you, no matter how experienced you are – accidents happen,” Sergeant Alford said.

“Rocks are slippery and it’s easy to lose your footing.”

Sergeant Alford said police would investigate any new leads.

He urged anyone with information to contact Halls Gap police on 5356 4411.

“We are still investigating the circumstances surrounding his disappearance,” Sergeant Alford said.

“At this time we are satisfied there is nothing suspicious.”

Police believe Mr VanDerWerf drove to the Grampians in the past 48 hours and was travelling in his grey 2005 Toyota Hilux with Victorian registration TSV 522.

The Toyota was located by police in a car park on Grampians Road, Bellfield, near Halls Gap.

Mr VanDerWerf is described as Caucasian, with a thin build and short greying hair.