Scientific evidence in the Sarah Payne murder trial remains strong despite doubts raised about possible contamination, a jury heard.

At Lewes Crown Court yesterday Sally O'Neill QC, defending Roy Whiting, questioned the reliability of each piece of evidence in questions put to the scientist who oversaw the forensic investigation into the schoolgirl's death.

It is the prosecution case that a series of fibres found on Sarah's body and shoe came from items found in mechanic and builder Whiting's white Fiat Ducato van, proving she had been inside on the night she disappeared.

The jury has also been told a single blonde hair, which has a billion-to-one link to Sarah, was found on a red sweatshirt also seized from the van.

Miss O'Neill questioned the scientific basis for assessing how rare each of the fibres were, suggesting the links proposed could have occurred purely by chance.

She said: "If you do not know how many of a particular fibre there is in the general population you cannot comment on the likelihood of a random match.

"I suggest to you that you do not have, in relation to these fibres, a reliable assessment of the likelihood of coincidence."

Mr Chapman conceded the strength of evidence from some individual threads was weak.

Asked about textured blue fibres of an unknown origin, which were found in a clump of Sarah's hair taken from the shallow grave where she was found and the red sweatshirt, he said: "If that's all we had in the case, it would not be very good evidence. It would be weak evidence but it is another part of the jigsaw."

He said the evidence taken together built up "extremely strong support" to a link between eight-year-old Sarah and Whiting, 42.

Miss O'Neill said: "It sounds to me like guesswork."

Concluding his evidence Mr Chapman said: "It's important to take everything into account. Individually, perhaps with the exception of the fibre from the clown curtain, none of the fibres are absolutely outstanding in their rarity. But it's the whole jigsaw that falls together."

Miss O'Neill had earlier suggested the blonde hair, which forms the central plank of the prosecution case, could have found its way on to the red sweatshirt during examination in the laboratory.

She told the court no trace of the hair had been found when the top was inspected and photographed by detectives on July 3, two days after Sarah vanished from a country lane in Kingston Gorse, near Littlehampton.

The court heard the sweatshirt was among 55 exhibits sent in one bundle to the Forensic Science Service laboratory in London, including several hairbrushes taken from Sarah's bedroom and the Payne family's home by PC Eric Prior.

When they were later examined, six of the exhibit envelopes had strands of animal and human hair stuck to the edges of adhesive tape left exposed when they were sealed, said Miss O'Neill.

A long, fine strand, which looked like the one found on the sweatshirt, was later tested and found to belong to Sarah's younger sister Charlotte, now six.

Miss O'Neill said there was the possibility that one of Sarah's hairs had similarly become attached to the bag containing the sweatshirt and then transferred on to the garment when it was being examined by forensic scientist, Zelda Kemp, who was the first person to open the bag.

Miss Kemp was asked if, when she examined the sweatshirt on July 4 last year, she had seen any hairs on the package.

She replied: "I cannot recall specifically handling this exhibit but, if I had seen a hair, I would have made a note of it."

PC Prior told the court how he had collected hairbrushes from the Payne family home in Hersham, Surrey, in the days after Sarah's disappearance, before her body was found on July 17 in a field off the A29 near Pulborough.

He said he placed each brush in a plastic tube before sealing the tubes in tamper-proof plastic bags.

PC Prior said he put the bags on the carpet of the landing at the Payne home, the point when it is suggested some hairs may have become stuck to the adhesive strip of each bag.

He added that he did not remember seeing any hairs on the bags.

Miss O'Neill said: "The hairs stuck to the outside could go anywhere couldn't they?

"It follows that there is absolutely no way of assessing how many hairs were stuck on any of those items because you never noticed them."

Whiting, formerly of St Augustine Road, Littlehampton, denies kidnap and murder.

The trial continues.

November 30, 2001