One of the men accused of murdering Stephen Lawrence may have picked up traces of forensic evidence when visiting one of the attackers, a court has heard.
Forensic scientist Roy Green told a jury at the Old Bailey that one of the scenarios he considered during his research was that David Norris had visited one of the killers and picked up fibres on his clothes.
A team of experts found six green fibres matching Mr Lawrence's trousers and one matching his T-shirt linked to a sweatshirt seized from Norris' house.
Stephen Batten QC, for Norris, asked Mr Green: "What you postulated to yourself is that he might know one of the real assailants for example, and have gone round to their address?"
Mr Green said: "That was one of the scenarios that I considered, yes."
The fibres expert told the court that he had also looked at the possibility that the sweater was washed after the attack.
But Mr Batten told him "you haven't a clue whether it was washed or not", and said he had only mentioned it because there were only a few fibres found. Mr Green said: "It was offered as one of the many scenarios which I had considered."
The fibres were found distributed all over the sweatshirt, which Mr Green said might be due to the garment being moved around after it was seized.
He added: "We do have to remember that what we see here is what remains after other fibres have fallen off and so it doesn't necessarily give a completely true picture of what was originally there."
Norris, 35, and Gary Dobson, 36, deny taking part in the gang attack in which Mr Lawrence was killed in Eltham, south-east London, in 1993.