Australia police were today questioning a man about the disappearance of Sussex backpacker Peter Falconio.

Brighton University graduate Mr Falconio, 28, vanished during a camper van trip through Northern Territory with girlfriend Joanne Lees.

Miss Lees told police the couple were ambushed by a gunman on a highway north of Alice Springs on July 14 last year.

Despite extensive searches, he has never been found, although a pool of his blood was discovered at the scene. He is believed to have been shot Today the Australian Associated Press said a man being held over a recent murder in Sydney was also being questioned over Mr Falconio's disappearance and suspected murder.

He is likely to be subjected to a DNA test, which would be compared with a sample taken from Miss Lees' clothing.

New South Wales police minister Michael Costa said he was discussing an exchange of forensic material between detectives hunting Mr Falconio's suspected killer.

Police in Sydney said they were co-operating with the investigation into Falconio's disappearance and apparent murder last July 14. But they declined to elaborate.

Northern Territory police spokeswoman Teresa Kuilboer said the man being held in Sydney was "a person of interest, like hundreds of others."

After Mr Falconio's disappearance Miss Lees, who lived with him in Hove, came under increasing scrutiny from the Australian Press over her account of the attack.

But police said they had no reason to disbelieve Miss Lees.

Miss Lees, 28, helped film a TV reconstruction of the attack. She recalled how the couple were flagged down by a man and her boyfriend got out to help.

She said she heard a bang, then a man in his 40s appeared at her side with a gun, tied her hands and forced her into his truck.

Police found crucial traces of DNA on Miss Lees' clothes, believed to be that of Mr Falconio's attacker.