The man was found washed up in mangroves on Saibai Island in the Torres Strait, a treacherous stretch of water that lies between the two countries.
The man, who claims to be Polish, is in immigration detention after being found on Saibai Island in the Torres Strait, authorities said.
Jo Meehan from the Australian Maritime Safety Authority said the man was found yesterday afternoon, 'ABC News' reported.
"We understand that he left Papua New Guinea at 3am yesterday morning on a raft made of twigs, sticks and string," Meehan said.
"We sent a helicopter from Horn Island and also a vessel from Thursday Island, and the locals in the area actually found him at about 2pm yesterday afternoon, and he had been washed up in the mangroves at Saibai Island," said Meehan.
She said the man is in good health despite sailing through monsoonal conditions.
"This is certainly a first for me. It's not something we would recommend people do.
"I am genuinely surprised that he got there. The weather in the area was around 40 knot winds with 1.5 metre swells," she said.
