AFP/London

Britain’s police watchdog yesterday said it could not investigate allegations that officers tried to smear the family of racist murder victim Stephen Lawrence, because it had not been given any evidence to support them.

Prime Minister David Cameron had led calls for answers after a former undercover officer claimed last month that he was part of an operation to spy on relatives of Lawrence, a black teenager who was stabbed to death by a white gang in 1993.

Former policeman Peter Francis said last month that he had posted as an anti-racist activist in order to discredit the campaign for a more thorough investigation into the notorious London murder. But the Independent Police Complaints Commission said yesterday that while the allegations made by Francis were “serious”, they could not be properly assessed because he has so far refused to speak to its investigators.

“The IPCC has determined that while the allegations by Peter Francis referred by the MPS (Metropolitan Police Service) are serious and indicate potential grave misconduct, there is as yet no information or evidence to support them,” the watchdog said in a statement.

Francis has previously said that he would only give evidence to a full-blown public inquiry. The murder of 18-year-old Lawrence is considered a milestone in British race relations. It sparked an overhaul of British policing after an official report found that “institutional racism” had tainted the original investigation. Police had quickly identified several suspects, but it took more than 18 years to bring the killers to justice. Two white men, Gary Dobson and David Norris, were convicted of the murder in January 2012 on the basis of new forensic evidence. They lost an appeal against their life sentences in August.

The IPCC also said yesterday that it would investigate claims that a former regional police chief tried to undermine a witness who gave evidence to the public inquiry into the original murder investigation.