The father of a British backpacker missing for more than two years in Cambodia said last night he hoped a £10,300 reward would help bring an end to his family's misery.

Mike Gibson, 59, and his ex-wife Jo made a national television broadcast during a visit to the capital Phnom Penh as part of a renewed effort to find out what happened to their son, Eddie Gibson.

Eddie, 21, from Hove, was three weeks into a combined Asian and Pacific studies and international management course at Leeds University when he left to travel around Cambodia.

Two weeks later, on October 24 2004, he sent his mother an email saying he was "really looking forward to coming home".

It was the last the family heard from him. When they went to collect him from a flight which left Bangkok, Thailand, on November 1, he never arrived.

Mr Gibson, a corporate financier, said two or three responses from people claiming to have information about the disappearance were being examined by the authorities after their appeal last Tuesday.

He said: "£10,000 is a life-changing sum of money in Cambodia and we hope that it will being us the information we need.

"We're not giving up hope. If Eddie had been the victim of a spontaneous robbery, we would have thought that a body would have come about by now.

"While we don't have the answers, there is still hope."

Four officers from Sussex Police's major crime branch spent ten days in Phnom Penh last summer working alongside the Cambodian National Police, but returned empty-handed.

The Gibson family joined forces in 2005 with Tim Blackman, the father of murdered air hostess Lucie Blackman, in the hope of drawing on the knowledge and experience he gained while searching for his daughter in Japan.