Police have suspended the search for 52-year-old Andrew Sharpe, who was mauled by a shark off Esperance on Western Australia's south coast on Friday.
"We don't hold any ongoing hope, unfortunately, for Mr Sharpe's survival", Senior Sergeant Justin Tarasinski told reporters.
Western Australia Premier Mark McGowan said the missing man was in the water with other surfers - as many as six to eight - and others were on the beach at the time of the attack.
"We have located two pieces of his wetsuit or a wetsuit that's believed to belong to Mr Sharpe ... not too far away from his last-known position".
Police divers and the Department of Primary Industries and Regional Development remote underwater vehicle team are involved in the search.
Rescue personnel searched for the man on Friday before suspending the operation until first light on Saturday.
However there was always an element of risk when entering the water, he said.
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"We know the deal when we go surfing".
"They're desperate to bring closure to Mr Sharpe's family", he added.
Mr Gowan brushed off calls for baited drumlines to be put into the water, instead saying a "swimming enclosure" - likely shark nets - would be offered to the Esperance community to help tourists feel safer.
"It's extremely sad to hear there's been a shark attack again", he said.
The attack was seen by around 8 other surfers and witnesses also reported a massive shark with a dorsal fin around a metre high was visible.
"It sounds like it's a very, very hard and very serious situation", McGowan said.
He said that the government had introduced extra safety measures to keep swimmers and surfers safe, including helicopter patrols, monitoring stations, and subsidised shark shields.