Investigations into the death of backpacker Peter Falconio, 28, were being scaled down today on the first anniversary of his disappearance.

But detectives have promised to leave no stone unturned in the search for Brighton University graduate's killer.

Mr Falconio was travelling in Australia with his girlfriend Joanne Lees, 27, who worked as a travel agent for Thomas Cook in Hove, when they were ambushed by a gunman on a deserted highway.

He vanished and it is thought he was shot dead, though no body has been found.

The couple lived together in Hove before their ill-fated trip.

A slew of rumours surrounding his death have grown up, all firmly denied by police, including recent speculation that he may have faked his own death in an insurance scam.

Northern Territory Police Assistant Commissioner John Daulby said he expected to take five officers off the 12-strong investigating team.

He said: "My thoughts go out to the Falconio family who have had a terrible time over the past 12 months, not only dealing with what they know in their hearts is most probably the death of their son, but also recent unfounded criticism of him.

"I know they will not be able to find peace until this case is resolved. I have assured them that with the help of the public this case continues to be very much alive.

"However, dependent upon the weight of information received, I expect to withdraw five members from its current strength of 12 later this month.

"We are determined to leave no stone unturned in our resolve to solve this investigation."

Miss Lees told police that a gunman ambushed them on July 14, last year.

She said the man flagged down their camper van as they travelled north of Alice Springs. He attacked the couple and attempted to abduct them.

Miss Lees was tied up but she managed to escape and hide in the bush.

Mr Falconio has not been seen since the attack although a blood trail was found by the roadside.