The BBC's Andrew Hoskins: "It is still a hit and miss affair"

But black people are still nearly five times more likely to be targeted than whites.

At the same time, street crime has risen by 10% since the results of the inquiry into the murder of black teenager Stephen Lawrence were published in February.

The inquiry accused the Metropolitan Police of "institutional racism", and queried the high incidence of stops and searches among ethnic minorities.

Author of the report, Dr Marian Fitzgerald: "There are issues that need to be explored"

But the author of Wednesday's report, Dr Marian Fitzgerald, was reluctant to blame police racism alone, saying the reasons for the disparity needed to be looked at more deeply.

She said: "We've got to get behind the statistics, get beyond the figures, and try to get the real picture."

10% of arrests

The power of stop and search was introduced for all police in 1984. Since then, it has accounted for about 10% of arrests.

But the high incidence of stop and searches among the black population has led to charges of police racism, and even police chiefs have admitted it is a "blunt instrument".

The interim report, compiled for the Home Office pending a full report in October, was based on seven pilot areas in London in which the police said newer, more systematic methods were used.

Assistant Commissioner of the Metropolitan Police Denis O'Connor: "We need to learn from history"

The report shows the methods improved arrest rates, which rose to about 18%.

The Metropolitan Police welcomed the figures, saying they showed stop and search could target the right people.

Met Police Assistant Commissioner Denis O'Connor said the practice remains an "essential tool for community safety", but he said the police were trying to use it in a "more sophisticated" way.

Training could be the answer

Wednesday's report says better training of police officers could be the answer.

Police handling of the Stephen Lawrence murder case shook public confidence

It says those planning searches needed to be aware of factors such as population trends in the area in which the operation is taking place.

For example, most searches were carried out on under-30s, and in four of the seven sites, ethnic minorities made up a majority of the population in this age range.

The Commission of Racial Equality's legal officer Barbara Cohen agrees: "This is what the Lawrence inquiry was urging all chief police officers to do.

"Get your forces to recognise that when you're exercising discretion, you'll be influenced by stereotypes and prejudices that you hold - not necessarily intentionally - or the outcome will be disproportionate and racist."

Practice a 'scandal'

But others questioned the entire ethos of stop and search.

The Lawrence report queried the practice of stop and search

Neil O'May, a solicitor who specialises in civil liberties, called the practice a "scandal".

He said: "The worst thing about it is the use of these powers has no benefit to society generally. Crime can be detected in the normal way."

Defenders of the stop and search tactic have pointed to the marked increase in street crime - up 10% in London - since the Lawrence inquiry.

Some argue crime is soaring because police are reluctant to carry out stop and search for fear of being branded racist.

Glen Smyth, chairman of the Metropolitan Police Federation, said an "anti-police culture" in the Home Office meant officers were failing to use the "extremely important" tool for fighting crime.

Mr O'Connor admitted "apprehension over accusations of racism" was one of the factors responsible for the drop in stop and searches since the Lawrence inquiry report was published.