A black teenager was “swallowed up” and knifed to death by a gang of white youths shouting racist abuse, a London court heard yesterday at the start of a high-profile murder trial dating back 18 years.

Prosecutors said detectives had uncovered new scientific evidence in the case of Stephen Lawrence, 18, whose murder on April 22, 1993 rocked Britain.

He was chased by the five-strong gang but was unable to escape as they pounced on him at a bus stop, the Old Bailey court in London heard as the trial of two men accused of murdering him got under way.

The college student was stabbed twice and he bled to death after two arteries were severed, prosecutor Mark Ellison told the jury.

Gary Dobson, 36, and David Norris, 35, both white men from south London, deny murdering the teenager.

Nobody has ever been convicted over Mr Lawrence’s death, which led to a major inquiry that concluded London’s Metropolitan Police was “institutionally racist”.