A SMUDGE of blood found on the T-shirt worn by Joanne Lees on the night she was attacked came from murder suspect Bradley Murdoch, a court was told today.

And an expert said the stain was 150 million billion times more likely to have come from Murdoch than any other caucasian male in Australia's Northern Territory.

Forensic biologist Ms Carmen Eckhoff told the court the bloodstain was found on the cap sleeve of Joanne's light blue French Connection T-shirt and a DNA profile was produced which matched the DNA sample from Murdoch.

Ms Eckhoff said: "It was profiled on December 31, 2003, and was found to be an exact match."

Asked whose DNA profile matched that produced from the bloodstain, she said: "Bradley John Murdoch."

Murdoch , 47, of Broome, Western Australia, has denied murdering Miss Lees' boyfriend, 28-year-old Peter Falconio, of Hepworth, Huddersfield.

He has also denied abducting and assaulting Miss Lees, now 32, formerly of Almondbury.

On the 12th day of the trial Ms Eckhoff said: "The probability of this profile appearing randomly in the Northern Territory caucasian population was 1.5 times 10 to the power of 17, to one."

She explained to the court this meant 150 followed by 15 zeros to one, or 150 quadrillion to one.

Murdoch laughed in the dock when Ms Eckhoff gave the court these statistics.

The court also heard that this bloodstain on Miss Lees's T-shirt was subjected to a more discriminatory test on January 21, 2003, and the results of this test also matched the DNA profile obtained from Murdoch later that year. The sample of Murdoch's DNA was taken from a mouth swab, which he had administered himself.

Ms Eckhoff said she analysed Murdoch's DNA sample once in February 2004 and once in dilution - as there was an excess of DNA in the original sample - in November 2004.

Asked to clarify her statistics by the judge, Ms Eckhoff said: "It means it's 150 quadrillion times more likely that it (the blood stain on Miss Lees's T-shirt) has come from Bradley John Murdoch than from another person selected at random from the Northern Territory."

She also told the jury that the bloodstain found on the highway where the incident happened was 3.8 quadrillion times more likely to have come from Peter Falconio than from another person selected at random.

Ms Eckhoff said several samples taken from blood on the remote highway where the two British backpackers were allegedly attacked near Barrow Creek, north of Alice Springs, and from bloodstained rocks and dirt nearby, matched a DNA sample taken from Mr Falconio's Ventolin inhaler.

Ms Eckhoff said that, while at Alice Springs examining the orange camper van the couple were travelling in, she was told that Mr Falconio was asthmatic and found his inhaler in the vehicle.

She said she swabbed the outside of the mouthpiece to obtain his DNA sample.

She said she took samples from several items at the scene of the incident, including a rock measuring 1cm by 1cm, the main blood pool on the highway, two reddish brown rocks nearby, a dirt mound which had a red stain and a small rock which was stained red on the dirt verge.

Every one of these samples produced a full DNA profile which matched that of Mr Falconio, the court heard.

Asked what the significance of a full profile was by Anthony Elliott, prosecuting, she said: "They were all good sampes and relatively fresh."

Ms Eckhoff also discovered a short white hair, which had a pointed shaft and appeared to have come from an animal, on a layer of tape used to construct the manacles which Miss Lees told police the attacker used to bound her arms behind her back.

It was sent for further analysis and to be compared to dog markers, but no DNA profile was obtained. The court heard the hair was also sent to a further expert.

During her evidence, Miss Lees said the attacker's dog was in the front cabin of the man's four-wheel drive vehicle when she was forced inside.

Samples were also taken from the "groove side" of the cable ties, from a portion of tape on the wrist bands and from the outside of the tape on the cable ties.

In each case, the DNA profiles obtained matched those of Miss Lees and of Vince Millar, the road train truck driver who rescued her and held the handcuffs while they were cut off by his co-driver Rodney Adams.

Miss Lees also told police she had rubbed lip balm into where the cuffs were around her wrists in a bid to loosen them and Ms Eckhoff told the court she examined a layer of tape within the centre-links of the cable ties on July 31, 2001.

"There was evidence of a red-pinkish substance, similar in appearance to how the lip gloss was described to me," she said.

"The cable ties did smell like strawberry and it had a consistency that looked like lip gloss."

Earlier, Ms Eckhoff gave a one-hour powerpoint presentation to the jury, explaining the methods and techniques used to analyse DNA samples.

The court heard Ms Eckhoff did not have access to Murdoch's DNA during the period when she was carrying out these tests and that such a sample did not enter her laboratory until November 17, 2003.

She also told the court that during the periods between examinations, the manacles were kept in a paper bag in an evidence box along with other items, each individually packaged, from the investigation.

She said the evidence bags were secured, intact and made of "heavy-duty paper" because plastic sweats in the heat and humidity of Australia's Northern Territory.

Ms Eckhoff said that if any DNA was on the outside of the bag then the items inside would not be contaminated, even if they were placed one on top of the other, as long as they remained sealed and intact.

Mr Falconio, 28, of Huddersfield, has not been seen since the night of the attack, and no body has been found.

His parents were in court listening to the scientific evidence and his mother, Joan, bowed her head down each time an image of the blood stain on the highway was shown.