A court has granted Australian police permission to analyse DNA taken from a man they want to question about the disappearance of British backpacker Peter Falconio.

Bradley John Murdoch, 44, was arrested in early September in connection with the abduction and rape of a woman and her daughter in South Australia.

South Australian Supreme Court Judge Ted Mullighan gave approval on Wednesday for the samples to be analysed by police in connection with the rape.

But lawyers for Mr Murdoch say they will appeal against the latest decision to the Full Court of the South Australia Supreme Court.

Until that appeal is heard, the DNA will not be analysed.

'Person of interest'

If the appeal is unsuccessful, South Australian officers will be free to pass the DNA samples to police in the Northern Territory, where Mr Falconio was abducted and possibly murdered last year.

Police in Northern Territory have described Mr Murdoch as a "person of interest" in Mr Falconio's suspected killing.

The attack happened on a Northern Territory highway

They want to compare his DNA with a sample gleaned from a blood stain found on the clothing of Mr Falconio's British girlfriend, Joanne Lees.

Mr Falconio was last seen alive in July 2001, when the couple were ambushed by a lone gunman who tricked them into stopping their van near Barrow Creek on an outback highway 300 kilometres (190 miles) north of Alice Springs.

Ms Lees was bound and gagged, and then forced into the back of the gunman's four-wheel drive vehicle after she heard a shot which may have killed Mr Falconio. He has not been seen since.

Ms Lees only escaped after hiding in scrub for six hours, later describing her attacker as a thin-faced man with long dark hair and a droopy moustache.

Manhunt

When she was eventually rescued Ms Lees was found to have blood on her t-shirt which was believed to belong to the gunman.

Police want to compare that blood with Mr Murdoch's DNA.

A pool of Mr Falconio's blood was found at the scene and police fear he is dead, although a manhunt has failed to find his body.

Mr Murdoch's appearance matches a description of Mr Falconio's attacker that Ms Lees gave to police.