Fibres expert Roy Green told a jury at the Old Bailey that he believed the wearer of a jacket seized from Gary Dobson was involved in the murder itself or had contact with the killer.
He said: “In my opinion, the combination of blood, DNA and fibres provide extremely persuasive evidence to link the wearer of the grey jacket to the attack itself or to contact with the perpetrator soon afterwards.”
Experts found 15 fibres on Dobson’s jacket that matched those from three items of Mr Lawrence’s clothing, and another fibre in the evidence bag the jacket was stored in.
They also discovered flakes of Mr Lawrence’s blood in the bag.
Dobson, 36, and David Norris, 35, deny taking part in the gang attack in which Mr Lawrence was killed in Eltham, south-east London, in 1993.
The prosecution argues that tiny amounts of fibre, blood and hair found on clothes seized from their homes prove they were involved in the murder of the 18-year-old student.
The defence says the samples got on to the clothes through contamination during handling and storage.
Mr Green said yesterday that if Dobson was not involved in the attack, then any transfer of fibres would have to be tertiary – that is, “from the victim to the offender and from the offender to Gary Dobson and from him to the jacket”.