Australian detectives have revealed they could be within days of solving the mystery of the disappearance of British backpacker Peter Falconio.

On Friday, a 44-year-old man will appear in court in Adelaide to face rape and kidnap charges unrelated to the Falconio case.

But officers will also ask the court to request he give a blood sample as they say he is "a person of interest" to them in relation to Mr Falconio, who disappeared in Australia in July last year.

Experts could make a DNA match within 72 hours

Court officials are expected to sanction the handing over of the sample to detectives in the Northern Territory, where the Briton vanished.

Within 48 hours they could know whether there is a match to any traces found at the spot where the 28-year-old was last seen.

Mr Falconio, from near Huddersfield, is believed to have been shot by a gunman who then attempted to abduct his girlfriend Joanne Lees after they were flagged down near the tiny outpost of Barrow Creek, 175 miles north of Alice Springs.

Miss Lees managed to escape and raise the alarm, but Mr Falconio's body has never been found.

Experts will also compare the man's DNA with a blood stain found on the dress Miss Lees was wearing when they were attacked.

A ministerial agreement has already been signed allowing the DNA profile to be handed over from South Australia to the Northern Territory.

Outpost

In June, DNA samples were taken from another man arrested over a stabbing in New South Wales but they did not match.

So far Australia's Northern Territory Police have made no arrests in relation to the case.

Last month, a year after he went missing, police in Australia vowed to leave "no stone unturned" in the inquiry.

But they simultaneously announced they were scaling back the investigation with the number of officers working on the case cut from 12 to seven.