A man arrested on suspicion of murdering Pc Keith Blakelock 25 years ago has been re-released on police bail.
Mr Blakelock was hacked to death during the Broadwater Farm riots in Tottenham, north London, in October 1985.
The 40-year-old man, originally from the Tottenham area, was arrested in February and answered bail early yesterday.
A Metropolitan Police spokesman said the man, who was 15 when the riots took place, has been told to report back to police again in early August.
It is believed the man may be serving a sentence at Highpoint Prison, near Haverhill, Suffolk, but police have refused to confirm or deny this.
Mr Blakelock, a father of three, was murdered by a machete-wielding gang during clashes with police on the estate.
Six people were originally charged with the murder, including Winston Silcott, Mark Braithwaite and Engin Raghip.
The three men were convicted of the killing in 1987 but cleared on appeal four years later.
Three youths were also charged with murder but did not face trial after a judge ruled their questioning was inadmissible.
One of them was Yardie gang leader Mark Lambie who was jailed for kidnap and torture in 2002 after terrorising the Broadwater Farm estate.
A fresh inquiry into the murder of Pc Blakelock was launched in December 2003 after a review identified new lines of inquiry could be pursued.
The murder case was never resolved despite an Old Bailey trial and the work of several teams of detectives.
Pc Blakelock and his colleague Pc Richard Coombes were attacked as they tried to protect firefighters when violence spiralled on the estate.
The unrest was sparked by the death of Cynthia Jarrett, 49, who collapsed during a police raid on her home.
Mr Silcott later accepted £50,000 compensation from the Metropolitan Police for their part in his wrongful conviction.
In 1994, two officers involved in the original inquiry were charged with fabricating evidence but cleared at the Old Bailey.
Ten years later police said they were confident of a breakthrough as they searched the garden of 16 Willan Road in Tottenham.
The painstaking search, a stone's throw from the murder scene, is not believed to have yielded any significant clues.
In 2005, police released images of Mr Blakelock's blood-stained overalls in a bid to provoke witnesses come forward.
Investigators have repeatedly said people in the area have information about the identity of the killers they have not shared with police.Reuse content