Murder trial jurors were taken on a "virtual walk" through a flat in which a teenage girl was engulfed in a ball of flames on Tuesday.

Watching on individual screens in a newly-opened high-tech courtroom at the High Court in Livingston, they were led through the smoke-stained hallway of the ground floor flat in Arbroath to the charred mattress where Jessica McCagh received burns so severe that she died within 24 hours.

Stewart Blackburn, 18, of Arbroath, denies murdering Miss McCagh, 17, by dousing her in petrol and setting fire to her in the flat, 83 Bloomfield Road, Arbroath.

He has admitted, however, that he did throw petrol about which then ignited, causing Miss McCagh's fatal injuries - a plea to culpable homicide that has not been accepted by the Crown.

The jury of 10 men and five women were shown a "Google-earth" style view inside and outside the flat, taken by an officer from the recently-formed Scottish Police Services Authority using a device called "Return To Scene", which takes 360 degree panoramic pictures and stitches them together using computer technology to create the virtual tour.

Backed-up by still photography, the tour allowed the jury to see details of smoke and fire damage to the flat.

They also saw a fire-damaged five-litre green plastic petrol can lying by the front door, a pink cigarette lighter on a kitchen counter, next to an empty bottle of lager and a jar of mayonaise, a blackened mobile phone lying in a wash basin, and the bodies of two dogs that also died in the blaze, on April 25th, 2009.

Pictures taken inside a hall cupboard showed another petrol container, a partly-dismantled motorbike, and an air-rifle.

Polce photographer Robert Bishop, who took the panorama, told Scotland's second most senior prosecutor, the solicitor-general Frank Mulholland, QC, that images flashed on the screen of the bedroom where it is alleged Miss McCagh was doused in fuel showed charred walls and "the remains of a burned-out bed with a mattress on it".

Mr Bishop was giving evidence on the second day of the trial of Blackburn, who also denies possessing cannabis, causing a breach of the peace by pointing an air rifle at two police officers and repeatedly pulling the trigger, and assaulting Miss McCagh in an earlier incident on April 25th by seizing hold of her, pulling her, slapping and punching her on the head, knocking her down, and pushing her.

The trial, before Lord Bracadale, continues.