A coroner has ruled out foul play in the case of missing prison boss David Prideaux, finding he died from either a medical problem or accident while deer hunting in the Victorian high country.

Mr Prideaux, general manager of maximum-security Barwon Prison, went missing while on a hunting trip with his brother-in-law near Mount Buller on June 5, 2011.

An extensive search of the area over the five following days failed to find any trace of the father of two, who was 50 at the time.

Police investigated speculation his disappearance was related to the 2010 bashing murder of gangland boss Carl Williams, who was an inmate at Barwon, and three alleged sightings of the prison boss.

But deputy state coroner Iain West said he agreed with the view of police, who believe Mr Prideaux died as a result of "a major medical event of serious accident that caused him to be incapable of movement or communication".