Pauline Dobson said she saw her son Gary, now 36, in the kitchen of the family’s home at the time Lawrence was murdered.

She said: “At half past 10 I went into the kitchen to make a cup of tea… Gary came down to make toast at 10.30pm, twenty to 11.”

She said her son, aged 17 at the time, was at home in his bedroom playing music and computer games.

Stephen Lawrence was murdered in Eltham, south east London, aged 18, at around 10.35pm on April 22 1993.

Prosecutor Mark Ellison QC said she told police she’d seen Dobson 10 minutes later than that when she was questioned in 1996.

He said: “This 10 minutes could be an extremely important 10 minutes between half past 10 and twenty to 11, because the people who attacked Stephen Lawrence could have been back in their homes by then… You saw Gary wearing not very much in the kitchen at twenty to 11 or a quarter to 11.”

Dobson also said her son had only worn one of the exhibits once – the Supertramp jacket which held key forensic evidence.

She also said he had never worn another exhibit – her husband’s cardigan.

Dobson told the court that he was frustrated with his life and menial job at the time of Lawrence’s death.

Yesterday Ellison asked him: “You were a group of people who shared and expressed amongst yourselves racist views, were you not.”

Dobson, giving evidence for a second day, said: “At that period yes, of course. It is indefensible, that. Yes.”