POLICE called in a school art teacher to help them investigate the disappearance of a Huddersfield backpacker in Australia.

But a court heard today the artist had no experience of police work and could not draw images of guns.

The Northern Territory Supreme Court heard today the art teacher with no knowledge of guns was asked to sketch the weapon allegedly used to kill Mr Falconio, 28, of Hepworth.

Mr Falconio has not been seen since July 2001.

It is alleged he was shot by 47-year-old Bradley John Murdoch on a remote Northern Territory highway.

Murdoch, of Broome, Western Australia, denies killing Mr Falconio and assaulting his girlfriend Joanne Lees.

Miss Lees, formerly of Almondbury, was allegedly tied up when the couple were ambushed on the Outback highway.

She managed to escape from her attacker's vehicle and hid in the bush.

Today the court heard that an Alice Springs art teacher was requested to act as a police artist in the case.

David Stagg said he had not worked in the role before and was extremely nervous.

He told the court he was asked to draw pictures of a gun and a vehicle from a description that was given by Ms Lees.

It took him six hours. The teacher said he was not familiar with guns and was not an expert in drawing them.

The trial judge has warned the jury that proceedings may run into Christmas.

The case in the Northern Territory Supreme Court has been set down for eight weeks and is now in its fifth week.

However, so far the jury has heard evidence from only 39 of an expected 80 witnesses.

The chief justice Brian Martin said there was no guarantee the trial would finish on time, as lawyers were notoriously inaccurate when estimating how long hearings would take.

The trial has also heard security cameras at a truck stop in Alice Springs were not set up to observe number plates.

The court was told yesterday that a suspect in the investigation into Mr Falconio's disappearance was caught on camera hours after the tourist disappeared.

Witnesses said the man on the video was Murdoch, but the number plate on the man's car was not recorded on security footage.

Today the court heard that cameras at the service station were set up to view the whole service station and could not zoom in.

The trial continues.