He was found by a fishing boat in the Sea of Okhotsk, the coldest sea in east Asia, according to the local prosecutor's office.

Russian media named him as 46-year-old Mikhail Pichugin and said he had set off along with his 49-year-old brother and 15-year-old nephew on a whale-watching trip to the Shantar Islands in early August.

At the time, a search was launched when they failed to return from Sakhalin Island, but to no avail.

The bodies of his brother and nephew were said to be still in the boat when a fishing boat rescued Mr Pichugin on Monday off the Kamchatka Peninsula.

He reportedly weighed only 50kg (7st 12lbs).

Russian media said the trio had a small amount of food and about 20 litres of water left when their engine failed.

It's currently unclear how the man survived and his relatives died.

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A video released by prosecutors shows Mr Pichugin in a life jacket and desperately shouting "come here!" as the fishing crew approaches.

The boat initially thought the tiny blip on their radar was a buoy or piece of junk.

"I have no strength left," he said as he was finally rescued.

An investigation has been launched into charges of safety violations resulting in deaths.