A backpacker from Richmond has gone missing after going for a run on a 135,000 acre ranch in Australia.

Australian police fear 18-year-old Sam Woodhead, who went missing near Longreach on February 12, has become lost or injured during a run, because his backpack and trainers were missing from his room.

Police turned up at the Richmond home of his family on Wednesday, February 13, after an owner of the station where he was staying reported him missing because his bed was empty.

His sister, Rebecca Woodhead, who turned 21 today said the news her brother was safe and well would be “the best birthday present ever”.

The last time he was seen was at about 5.30pm on Tuesday, February 12, by a friend he met while working on the ranch.

A search party of 200 volunteers, two helicopters, quad bikes and planes are circulating the area in search of the former Brighton College student.

His sister Rebecca said: “He’s got a cool head. I’ve always said he is very grown up for his age. He can muck about like any teenage boy but I’ve always said he is pretty sensible in this sort of situation. I haven’t slept since we heard about it.”

The last time his family saw him was just before Christmas when he embarked on his gap year trip, and the wannabe marine hoped to get a place at Sandhurst upon his return in October this year.

His father, 62-year-old Peter Woodhead, said the family was staying positive and were in contact with an ex-nanny of his children, Katrina, who lives in Brisbane.

He said his son, who used to run in Richmond Park with weights in a rucksack, was a fan of Bear Grylls’ survival programmes.

He said: “We have all seen things like this on TV where you really feel terrible anguish for the families involved but at the moment in the light of things we are being positive and upbeat.

“He could just turn up at the farm and ask what all the fuss is about which would be typical of him in a way but on a serious note we are seriously concerned.”

He said his son, who is a very fit and athletic young man, had been working on the farm for about a month.

He said: “He was looking at it as an experience to improve his chances of pursuing his career rather than carousing the beaches and bars. It’s one thing doing it on the plains of Dartmoor, probably another thing doing it at 18 on your own in the outback.”

The missing teenager’s mother, Claire Derry, 54, caught a flight to Australia from Heathrow yesterday, February 14, because she could not cope with waiting by the phones.

A search party of 200 volunteers, two helicopters, quad bikes and planes are circulating the area in search of the ex-Brighton College student.