A black security guard was stabbed by the sixth suspect in the racist murder of Stephen Lawrence while he claimed he had previously killed.

According to the victim, Matthew White told him there had been no consequences for killing “Stephen” in the 2015 attack.

Although White was jailed for four months, he was not charged with racially abusing or attempting to harm the guard.

It apologises “if this investigation was not conducted as it should have been”.

According to this man, White admitted that he was involved in Stephen’s attack after police failed to properly investigate him.

The heroin user attempted to stab his victim with a used syringe needle while using racial slurs as he shoplifted from Lidl in Eltham, south-east London. “I will kill you, I have done it before, nothing will happen,” White told the former security guard.

Stephen Lawrence’s 1993 stabbing was still under investigation by the Met at the time. In 2012, two of the killers were jailed, but police consistently stated that six people were involved. The security guard was never contacted by police regarding the murder case, despite ongoing inquiries.

An Eltham gang of white youths stabbed Stephen to death as he waited for a bus when he was 18 years old. This is one of the most notorious racist killings in the UK.

After a disastrous Met Police investigation failed to bring anyone to justice, a landmark inquiry concluded that the force was institutionally racist.

Matthew White was found to have admitted to being present when Stephen was attacked, and he appeared to be the unidentified fair-haired lead attacker described by eyewitnesses in 1993.