A sixth man held over the murder of black teenager Stephen Lawrence in 1993 will not be charged after prosecutors said there was insufficient evidence.
The Crown Prosecution Service said no further action would be taken against the man, who has not been named and was arrested 11 months ago.
"After careful consideration it has been decided that there is insufficient evidence for a realistic prospect of conviction," deputy chief crown prosecutor Lionel Idan said.
Mr Lawrence was 18 when he was stabbed to death by a group of up to six white youths in an unprovoked attack as he waited at a bus stop in Well Hall Road, Eltham, south east London, with a friend
An investigation has been launched over the conduct of one serving and two former Met Police officers in relation to the Stephen Lawrence case.
The Independent Police Complaints Commission will investigate allegations of discreditable conduct and breaches of honesty and integrity by Commander Richard Walton.
He is accused of meeting with an undercover officer in 1998 and obtaining information about the family of Lawrence and their supporters "potentially undermining the inquiry (into Stephen's murder) and public confidence", the commission has announced.
They will also investigate allegations of discreditable conduct on the part of two former Met officers - then Detective Inspector Robert Lambert and Commander Colin Black.
The IPCC started the probe after the Stephen Lawrence Independent Review undertaken by Mark Ellison QC.
The mother of Stephen Lawrence is being tipped as Labour's candidate to fight the 2016 London mayoral elections.
Doreen Lawrence has campaigned for justice since her teenage son was murdered in 1993, and was named the most powerful woman in the country in a list compiled for Radio 4's Woman's Hour.
Labour policy coordinator Jon Cruddas MP wrote in The Sunday People that the "influential and dynamic" peer is "a class act and going from strength to strength".
A Labour Party spokeswoman said: "The Labour Party's selection process for our London Mayoral candidate is not yet under way."
Two men were arrested on suspicion of criminal damage following an incident at the Stephen Lawrence memorial plaque in southeast London, the Metropolitan Police said.
Police said the pair are alleged to have spat at the memorial and broken a flower pot.
The men, aged 18 and 19, have since been released on bail until May 29th.
Home Secretary Theresa May has said it may be difficult to find out who was responsible for authorising an undercover police officer to spy on the family of Stephen Lawrence.
But Mrs May assured MPs that "every effort" will be made to ensure the truth comes out in the numerous investigations and inquiries into the police's conduct after Stephen was killed.
She spoke after Labour's Diane Abbott called for an assurance the identity of whoever authorised the Special Demonstration Squad's (SDS) "spy in the Lawrence camp" will be revealed.
But Mrs May suggested that Scotland Yard's record keeping on its own investigations into police corruption may make it difficult after the review also revealed the mass shredding of key evidence in 2003.
She said: "I think everybody in this House and across the country was shocked at the findings of the Ellison review, particularly in relation to the question that there was somebody from the
Special Demonstration Squad who was, in the terms that Mark Ellison put it, effectively a spy in the camp around the Lawrence family.
"Every effort will be made to ensure that the truth comes out in relation to this."
Scotland Yard is to request a private meeting with the parents of murdered teenager Stephen Lawrence to share the findings of the criminal investigation into alleged misconduct by undercover officers.
The force is writing to Doreen and Neville Lawrence in order to discuss Operation Herne, the probe into Scotland Yard's Special Demonstration Squad (SDS) - the top secret unit that was up and running for nearly 40 years.
The brother of murdered teenager Stephen Lawrence has said he would agree to take part in a probe into police records following a damning report which found that officers spied on his family.
Metropolitan Police Commissioner Sir Bernard Hogan-Howe plans to appoint an "independent multi-disciplinary team" to search the force's archives for any available evidence for a public inquiry into undercover policing.
Speaking to the BBC, Stuart Lawrence said: "I reserve judgment until I hear who he's tried to employ to try to do this job and I wouldn't mind being part of the team myself to ensure the job is done".
The mother of murdered teenager Stephen Lawrence has demanded the Metropolitan police chief take "decisive action" after a damning report found officers had spied on her family.
Baroness Lawrence has urged Sir Bernard Hogan-Howe to co-operate fully with the judicial inquiry ordered by the Home Secretary following the Ellison review's "devastating" revelations, in a letter seen by the BBC.
A report by barrister Mark Ellison QC published this week found that one of the officers on the original investigation into Stephen's death, detective sergeant John Davidson, may have acted corruptly.
It was claimed that Davidson had admitted having a "corrupt connection" with Clifford Norris, the gangland boss father of David Norris, who was finally convicted of Stephen's murder in 2012.
An undercover officer who allegedly "spied" on the Lawrence family disclosed details concerning the separation of Stephen Lawrence's mother and father, Doreen and Neville.
The officer - known as N81 - reportedly "touched on personal details" concerning the family to the Special Demonstrations Squad (SDS) during the 1998 inquiry into Stephen Lawrence's death, according to the Ellison report.
Neville Lawrence labelled the claims as "disgusting", telling the Daily Mail: "It's unbelievable. They have mocked everything we have done, telling us to our faces that they are listening and things will change, and all the time laughing behind our backs.
"I think they are actually worse than criminals because these officers get paid with taxpayers' money for what they do."
A senior Met Police officer has been moved from his role following the publication of a report into Stephen Lawrence's murder investigation.Read the full story ›