A 26-year-old Australian man who went missing two weeks ago in a remote Malaysian mountain range has been found emaciated and with leeches on his legs in a treacherous stretch of thick jungle.

Andrew Gaskell, an engineer who was trekking alone through Asia to "come to some sort of conclusion as to who I am", entered the Mulu national park in Borneo for a week-long hike on October 18.

He was declared missing several days later after failing to make contact with family or friends.

Following a frantic search by Malaysian authorities, Mr Gaskell was discovered “weak and happy” at 12.30pm on Tuesday, about 22 yards (20 metres) off a hiking track in the Hidden Valley, an inhospitable section of the park known for its harsh terrain and network of gorges, steep cliffs and vast limestone caves.

Despite appearing gaunt and frail, he was apparently conscious and was able to speak to his rescuers before he was airlifted to a nearby hospital.