A man accused of raping two women in Australia is also being quizzed over the death of missing backpacker Peter Falconio.

The arrested 44-year-old's identity has not been released and police gave no reason for linking him with Sussex University graduate Mr Falconio, who disappeared just over a year ago.

And they were cautious about raising hopes of a breakthrough in the high profile case.

John Daulby, acting deputy commissioner of Northern Territory Police, said: "As with other persons that have been brought to our attention in respect to the disappearance of Peter Falconio, this person is at this stage no more than a person of interest."

Mr Falconio, 28, is believed to have been shot by a man who then attempted to abduct his girlfriend, former Hove travel agent Joanne Lees, on the Stuart Highway north of Alice Springs on July 14 2001.

Ms Lees, left tied up in the man's pick-up truck, managed to free herself and hid in the Outback for six hours before flagging down a passing truck.

She returned to England last year and has since criticised Northern Territory police for their lack of progress in the case.

Northern Territory police never found Mr Falconio's body and have made no arrests despite launching one of the nation's biggest manhunts.

A South Australian police spokeswoman said the man now being investigated in relation to Mr Falconio was arrested on Wednesday night in Port Augusta, 800 miles south of where Mr Falconio disappeared.

He was charged with two counts of rape, two counts of unlawful detention and firearms offences.

He appeared before Port Augusta Magistrates yesterday and was ordered to be held in custody to reappear in court on September 6.

South Australia police are likely to compare DNA samples from the man with samples taken at the scene of Mr Falconio's disappearance. The process could take days, they said.

However, officers are cautious about raising expectations after a false alarm earlier this year. In June a man arrested by police in New South Wales over a stabbing death fitted the description of Mr Falconio's suspected murderer but was cleared by DNA testing.

Both Miss Lees and Mr Falconio originally came from the Huddersfield area of West Yorkshire. They shared a home together in Hove before their trip abroad.