According to a secret Met Police report uncovered by the BBC, a senior officer involved in the Stephen Lawrence murder case was corrupt,
The officer, Ray Adams, was cleared by a corruption probe which relied on false testimony from a man linked to the family of one of Stephen Lawrence's killers.
The revelation contradicts years of police denial about the role of corrupt officers in the case.
Mr Adams said he has asked the Met to investigate the allegations.
The BBC says the Metropolitan Police did not answer its questions about the report's conclusions regarding Mr Adams, only saying it will review material before deciding whether any further action is required.
Imran Khan, solicitor for Stephen's mother Baroness Lawrence, said the report about Mr Adams - a former commander, who was once head of criminal intelligence for the entire Met - was "dramatic, disturbing and shocking".
Sir William Macpherson's landmark 1998 public inquiry into the murder did not hear about this link between Mr Adams and the informant.
Fourteen years later, the Met said there was no suggestion of any relationship between the two.
Eighteen year-old Stephen Lawrence, the son of Jamaican immigrants in Britain, was murdered in April 1993 in a racist attack by a gang of young white men in Eltham, south-east London. The failure to bring the killers to justice prompted a national outcry. Two men were eventually convicted in 2012. Other suspects have never been convicted.
SOURCE: BBC