THE Huddersfield family of backpacker Peter Falconio faces an agonising wait before learning whether the drug runner found guilty of his murder has succeeded in appealing his conviction.

Lawyers for Bradley Murdoch, 48, argued that he suffered a "substantial miscarriage of justice" at his trial in Darwin, Australia, last year.

The three judges hearing the appeal in the Northern Territory Court of Criminal Appeal in Darwin adjourned the case today after three days of legal submissions.

They reserved their decision and are expected to deliberate for several months before delivering a written judgment next year.

Murdoch is serving life for murdering 28-year-old Mr Falconio on a remote stretch of highway near Barrow Creek, about 200 miles north of Alice Springs, on July 14, 2001.

The mechanic was also found guilty of abducting and assaulting Mr Falconio's girlfriend, Joanne Lees, a 33-year-old support worker originally from Almondbury.

Ian Barker QC, counsel for Murdoch, urged the judges today to order a retrial if they upheld any one of the grounds of appeal.

Murdoch's defence team has argued the trial judge should have excluded Miss Lees' identification of Murdoch in a photograph line up because she had already seen his picture on the internet.

In August 2002 a friend directed Miss Lees to the BBC website, which included a photograph of Murdoch and described him as Australian police's prime suspect for the murder of Mr Falconio.

Five weeks later, when police showed her a photo board of 12 different people, she correctly picked out Murdoch, the appeal heard.

Miss Lees again identified him in the dock at a committal hearing and at last year's trial.

But Rex Wild QC, for the Crown, said Miss Lees had not gone on to the internet looking for a picture of her boyfriend's killer.

He told the court: "Even though the evidence of the victim clearly is important evidence, it was not vital to the Crown case ultimately."

The Crown has argued that Murdoch received a fair trial and that his conviction is safe because of the "very damning" DNA evidence against him.

Police found Murdoch's DNA in a blood stain on Miss Lees' T-shirt, on the home-made handcuffs he used to tie her up, and on the gear stick of the young couple's camper van, the court heard.

Mr Wild said: "My learned friend makes much of the fact that this is a case about identification.

"The most compelling evidence about identification in this case is the DNA evidence, which has not been challenged in this appeal."

Murdoch's lawyers also attacked evidence given at trial by Dr Meiya Sutisno that Murdoch was a man captured on CCTV footage at a truck stop near Alice Springs just hours after Mr Falconio's murder.

Dr Sutisno's field of expertise of "face and body mapping" was untested "pseudo-science" and the judge should have excluded her testimony, Mr Barker told the court.

Murdoch's defence also claims his minimum non-parole period of 28 years is "manifestly excessive" because it means he is likely to die in prison.

Even if the judges at the appeal - which was not attended by Murdoch, Miss Lees or Mr Falconio's family - do not order a retrial, they have the power to cut this sentence.

If this bid to overturn his conviction fails, Murdoch can apply for special leave to appeal to the High Court of Australia, although his lawyers have not indicated whether they would do this.