Home Office pathologist Dr David Rouse who carried out the post mortem on the body recovered from a shallow grave in the back garden of a house in Margate, Kent, in 2007 told the High Court in Dundee bruising found behind the voice box was consistent with "death by neck compression".

He also said there was no evidence of disease as a natural cause of death, no obvious signs of major blunt or sharp penatrative injury, no fractures and no cuts, but said he had made it "quite clear" on the death certificate that he had recorded the cause of death as "unascertained".

Donald Findlay QC, who is defending Peter Tobin, the man accused of the abduction, sexual assault and killing of the tragic Redding teenager in 1991, suggested Vicky might have died of fright.

He put forward a number of "possible scenarios" to Dr Rouse for comment, including that possibility.

In his cross examination he asked: "Is it not a matter of fact we do not know the cause of this girl's death and from the information we have we're never going to know? This girl died of natural causes and these natural causes have not been ascertained? This girl died for some reason of some cause, even from fright, but we just don't know? Teenagers just die."

Solicitor Frank Mulholland QC, prosecuting, challenged the idea that a healthy 15-year-old girl on the way home to see her mother would simply drop dead.

Earlier Dr Rouse had told the court the detailed examination of the remains was conducted in the Queen Elizabeth, The Queen Mother's
Hospital in Margate on Tuesday, November 13, 2007, the day after they were found.

Dr Rouse confirmed that Vicky's body was cut in half with a knife after she had been killed and that her arms and ankles were bound with ligatures made from a material similar to sash window cords.

He said he was given two body bags. One contained the upper torso wrapped in plastic bags, a piece of blue curtain and a white cloth. He confirmed there was a ligature around the body part which was also clothed in a sweatshirt, polo shirt and bra. There was a bracelet on the right wrist and a ring on the middle finger of the left hand.

He said the second body bag held the lower torso which had been placed in three black, two green and two dark coloured bin bags with a piece of cloth and a ligature had been found around the ankles.

The expert told the hushed court: "My overall impression was the body was fairly well preserved, surprisingly so. With a body that's been in the ground for 10 to 20 years you would expect a fairly difficult post mortem but in truth this one was fairly easy. The organs were well preserved, probably because the body had been kept cool and dry and not attacked by flies as it had been sealed in plastic bags. Temperature is an overwhelming factor. The cooler the body, the longer it will stay in a fresh state. Insects can turn a body into a skeleton in a few weeks."

Dr Rouse told the murder trial the state of decomposition suggested death 10 to 20 years ago and were consistent with Vicky's disappearance in 1991.

The trial before Lord Emslie continues.