A man who had been adrift on a dinghy for two months was rescued, but the bodies of his brother and nephew were reportedly found on the ship.
According to local prosecutors, it was found by a fishing boat in the Sea of Okhotsk, the coldest sea in East Asia.
Russian media reported that the person was 46-year-old Mikhail Pichugin and said that in early August, together with his 49-year-old brother and 15-year-old nephew, he set out on a cruise to the Shantar Islands to observe whales.
At that time, a search was launched when they did not return from Sakhalin, but to no avail.
The bodies of his brother and nephew were said to be still in the boat when a fishing boat rescued Pichugin off the Kamchatka Peninsula on Monday.
It reportedly weighed only 50 kg (7st 12lbs).
Russian media reported that after the engine failure, the trio was left with little food and about 20 liters of water.
For now, it is unclear how the man survived and how his loved ones died.
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The video released by prosecutors shows Pichugin wearing a life jacket and desperately shouting “come here!” as the fishing crew approached.
The boat initially thought the tiny blip on their radar was a buoy or a piece of scrap metal.
“I have no strength left,” he said when he was finally rescued.
An investigation has been launched into allegations of security breaches resulting in death.