Criminologist Dr Bonny Mhlanga of the University of Hull examined 5,000 cases of young people coming in front of criminal courts.

He found that while defendants from different backgrounds and different parts of the country were treated differently, there was no evidence of unfair discrimination against ethnic minorities.

And in some cases, black and Asian defendants appeared to receive more favourable treatment than white defendants.

The research suggests that black and Asian defendants were more likely to have their case dismissed, or be acquitted, at magistrates' courts.

'Different picture'

"Evidence published to date often suggests that ethnic minorities receive harsher treatment from the police and the courts," said Dr Mhlanga. "A different picture is presented in this report.

"We have seen that, at the CPS level of the criminal justice system, Asian, black and other minority defendants have often received more favourable outcomes from CPS lawyers' decisions than their white counterparts."

The report finds that the CPS is acting independently of the police - as it is meant to - in choosing appropriate cases for prosecution, and downgrading or rejecting cases where the police have brought inappropriate charges against minorities.

It adds that, if anything, the CPS may be discriminating in favour of ethnic minorities.

The study covered 13 CPS areas in England and Wales and a total of 6,144 young defendants whose cases finished between 1 September and 31 October 1996.

Within each CPS area, the study covered the 22 branches with the highest proportion of residents from ethnic minorities.

The Director of Public Prosecutions, David Calvert-Smith, said: "The CPS welcomes this study and we are pleased that it shows we seem to be exercising our independent and impartial role."