On Friday afternoon he will be interviewed by Swedish police.
The man was plucked out of the sea by the Berge Odin, a Norwegian gas tanker which was on its way to Sweden from the UK. He will be handed over to the Swedish authorities in Stenungsund.
“The man was lying on a wooden pallet tied to a few oil drums,” said the rescue leader Asbjørn Viste to Norwegian news agency NTB.
“He claims that he was thrown overboard from another ship. He’s a bit cold and worn out but as far as we can tell he has no physical injuries.”
The man, who speaks fluent English, has not given any more information about how he ended up floating in the middle of the sea – or about who he is.
However, he has expressed a desire to be introduced to the Swedish authorities when the ship reaches harbour. That has led Swedish police to suspect that he may be an asylum seeker.
“It’s most likely, I think, that this is an asylum case,” said Lars Skoglund at Östra Götaland police to Svenska Dagbladet.
“But it could also be some sort of crime since the man maintains he was dumped at sea.”
The ship will not be able to moor in Stenungsund until Saturday. However, it will anchor outside the port on Friday afternoon when the Swedish coastguard and sea police will board to meet the mystery man.