By Agence France-Presse
Andrew Gaskell, 26, had set off alone on October 20 into Mulu National Park, which is at the heart of vast and rugged rain forests on Borneo island.
Gaskell got lost after eschewing local park regulations requiring that visitors take a guide, district police officer-in-charge Gabriel Marudi told AFP by phone.
But he was found on Tuesday afternoon after a nearly week-long jungle search by around 40 rescue personnel.
Gaskell was thin and weak and had an injured foot but was flown by helicopter to the town of Miri and was expected to recover, Marudi said.
"It was very lucky for him to be found still alive after such a long time," said Marudi, adding he had no further details on how Gaskell survived.
Mulu National Park is a UNESCO world heritage site famed for some of the world's largest caves, striking limestone karst pinnacles above ground and dense jungle.