POLICE investigating the murder of PC Keith Blakelock yesterday finished digging up a garden yards from where he was killed.

But a spokeswoman refused to comment on reports that an "item of interest" recovered by specialist search teams working at 16 Willan Road, in Tottenham, north London, was a machete.

She said the item was still undergoing forensic testing.

PC Blakelock, a 40-year-old father-of-three, was murdered by a machete-wielding gang during the riot on the Broadwater Farm estate, in October 1985.

Sunderland-born PC Blakelock and his colleague PC Richard Coombes were attacked when they went on to the estate to protect firefighters as the violence escalated.

Scotland Yard yesterday said it was pursuing new lines of inquiry thrown up as a result of publicity surrounding the excavation, including information from someone in the North of England.

Scotland Yard Commander Andy Baker, head of homicide for the Metropolitan Police, said forensic teams still had "a great deal of work" to do.

He said: "Over six tonnes of soil which have been removed from the garden will now be examined at a separate location.

"Officers will be painstakingly sifting and searching the soil by hand in a bid to locate fragments of evidence.

"We know that there are many more people out there who have information about Keith's killers and the people who tried to kill Richard.

"I am hopeful that they too will find the confidence to come forward and speak to us."

He said although the search at Willan Road ended yesterday, work at the address would continue for a few days to restore the garden to its original state.

"We know that this activity has brought back painful memories for some residents, and officers have worked hard to minimise the disruption and distress to all on the estate," Superintendent Tony Eastaugh said.

The painstaking search, aided by forensic archaeologists, came after intelligence that vital evidence may have been buried there shortly after the killing, according to Cdr Baker.

Weapons were discovered at the time but PC Blakelock's helmet has never been found.

It is thought that the bloody clothing of the killers could be recoverable for DNA testing.

Winston Silcott, Mark Braithwaite and Engin Raghip were convicted of the murder in 1987 but cleared on appeal in 1991 because of "unsafe" police evidence.

Silcott was released from prison last year after serving a sentence for another murder.