Unknown man's DNA found on underwear next to Xue's wife's body

Nai Yin Xue is accused of killing wife An An Liu (top right) and leaving daughter Qian Xun Xue, also known as 'Pumpkin', at a Melbourne train station. Photos / Paul Estcourt / Supplied

Traces of DNA from two unidentified men were discovered on underwear found in the car boot which contained the body of An An Liu, a court was told today.

The evidence was given by a forensic scientist at the trial in the High Court in Auckland of Nai Yin Xue, 55, who denies murdering Ms Liu in September 2007.

The underwear was found in the boot of Xue's Chinese Times car, along with the body of Ms Liu, 28, when the boot was opened at a secure police compound on September 19, 2007.

Police officers said the items in the boot included a yellow tie around her neck, a green dressing gown that prosecutors say is Xue's covering her, pink pyjama pants, red underwear, and a jacket with two men's rings in the pocket, including a wedding ring.

Forensic scientist Sally-Ann Harbison said the ends of the tie and the waistband of the underwear were found to have DNA very likely to be that of Ms Liu in initial testing.

She said other DNA was detected but of an unsuitable amount for the initial testing to produce any clear results, and she was therefore asked to conduct a more sensitive YSTR test, which can find very low levels of male DNA.

Ms Harbison said the test found DNA which was very likely to be that of Xue on both the tie and the underwear waistband.

It also found DNA of one other unidentified man on the tie, and at least two unidentified men on the underwear waistband.

She said it was likely but not certain that the male DNA on the tie and the male DNA from one of the two unidentified men on the underwear came from the same man.

None of the DNA profiles matched that of Zheng Ye Zhang, who lived on the property with his wife, along with Xue and Ms Liu, Ms Harbison said.

Ms Harbison said the amount of DNA of the man very likely to be Xue on the tie and underwear was probably smaller than a pinhead.

She said the amount of DNA of the unidentified man on the tie was " smaller still by about 10" than that of the man likely to be Xue, and the unidentified DNA on the underwear about five times smaller than that likely to be Xue's.

Under cross-examination from Xue's counsel Jesse Soondrum, Ms Harbison said it was not surprising Xue's DNA was on the tie and the underwear given they lived in the same house.

She said it was less common to find DNA of two men who didn't live in the house on the pair of underpants, assuming they were regularly washed.

"It is possible for male DNA to survive a wash but it is unusual and it would be surprising to find so many contributors on a pair of underwear," she told the court.

Prosecutors say Xue strangled Ms Liu with the tie found on her body, probably on September 11, 2007.

They say he then fled to Melbourne with the couple's three-year-old daughter Qian Xun Xue two days later, and then abandoned her at a Melbourne train station on September 15 before flying to the United States. He was caught there in February 2008.

The Crown is expected to close its case by early afternoon tomorrow.

The trial before Justice Hugh Williams and an all-woman jury is into its third and probably final week.

- NZPA