Police yesterday called off the search for Wellington man Scott Oliver (41), known as Brock, and said they now believed the missing man had drowned in a gorge in the upper reaches of the river.
''Tragically, we have no option than to accept that Mr Oliver has been swept into the gorge and been drowned,'' Wanaka police SAR co-ordinator Sergeant Aaron Nicholson said in a statement.
The decision came after a fruitless second day of searching by LandSAR Wanaka search and rescue volunteers, who tracked Mr Oliver's footprints into the gorge but could find no trace of an exit, Sgt Nicholson said.
Mr Oliver had been camping on a river flat called ''Jumboland'' with his partner, his partner's brother and his partner's father.
He was last seen at 6.30pm on Sunday, when he separated from the rest of the group to attempt a shortcut through the gorge while returning from a day trip to Lake Lucidus, Sgt Nicholson said.
The gorge area was a relatively short, 300m jumble of ''huge boulders and raging water''.
''We are certain that we know where Mr Oliver went into the gorge, and we are certain that he has not come out,'' Sgt Nicholson said.
''This is a very dangerous area and in the absence of any further clues there is unfortunately little else that we can do.''
The search, including river rescue specialists, was conducted on foot and by air.
LandSAR Wanaka spokesman Phil Melchior said areas of the river ''simply cannot be searched'', despite the water level being ''relatively low''.
Searchers had reported that even before the start of the gorge itself, the water, while clear, was running so swiftly that even calf-deep it was difficult to stand up in, he said.
''It would be like trying to search inside a giant washing machine which cannot be turned off,'' Mr Melchior said.
''Anyone losing their balance while trying to cross had almost no chance of getting out again once in the gorge.''
The matter would be referred to the coroner.
