Approximately 80 people are this weekend involved in the search for missing Brett Hall in the rugged terrain of Whanganui River.
Since Mr Hall went missing Police have been assisted by volunteer LandSAR and a small number of Army personnel to carry out a range of searches over a 16 to 20 square kilometre area.
This weekend the numbers have been significantly boosted to cover as much ground as possible. Specialist alpine rescue volunteers from Palmerston North, Ruapehu and Taranaki have joined the operation to abseil into areas too difficult to reach on foot and an RNZAF Iroquois is assisting with dropping searchers from the base camp into specific areas.
The weekend search operation kicked off at 9am and will continue until nightfall. Searchers will then camp overnight and continue again until nightfall tomorrow.
Senior Sergeant Darcy Forrester said: "The majority of the searchers are volunteers who have day jobs and are giving up their entire weekend to help this operation; we couldn't do what we do without their significant and invaluable support.
"An operation of this size is not typical but the terrain is not typical and we are also mindful that there is a homicide investigation running in parallel to our search. The more area we cover without finding Mr Hall, the more that will assist the homicide team in determining whether or not there is an innocent explanation for his disappearance."
Police are still appealing for people who have been to Mr Hall's property in recent months to come forward, in particular the driver of a white flat deck ute seen leaving the track to the property around 7pm on Sunday, 29 May.
Anyone with information relevant to this investigation is asked to contact Whanganui Police on 06 349 0600. Alternatively information can be provided anonymously via Crimestoppers on 0800 555111.
Media enquiries should be referred to Communications Manager Kim Perks on 027 234 8256.