Police have asked witnesses for permission to pass on statements

This comes after a decision in May 2004 by the Crown Prosecution Service not to go ahead with a new prosecution after a five-year police reinvestigation.

Stephen was stabbed to death in an attack by a gang of youths in Eltham, south-east London, in 1993.

It is understood police have visited witnesses to gain permission to pass their statements to Stephen's family.

In 1993 five youths were arrested over the murder.

'Unprovoked racist attack'

Luke Knight, Neil Acourt and Gary Dobson were acquitted of the murder after their trial collapsed in 1996.

Proceedings against Jamie Acourt and David Norris never went to trial.

A Crown Prosecution Service spokesperson said: "We have asked police to assist us by contacting some witnesses who provided statements during the investigation in order to seek their consent to disclose the content of their statements.

"This is in order to answer questions raised by them so that we are able to provide as full an explanation as possible of CPS advice in the case."

The Lawrence family solicitor, Imran Khan, said he would be making no comment until the statements had been fully examined.

A 1997 inquest ruled Stephen had been "unlawfully killed in a completely unprovoked racist attack by five white youths".