Black people are nearly seven times more likely than white people to be stopped and searched by police in Hammersmith and Fulham - the fourth-highest "disproportionality" rate in London.
Only black people in Wandsworth (9.1 times more likely), Lambeth (7.3) and Tower Hamlets (7.2) have higher disproportionality rates, according to figures published by the Equality and Human Rights commission.
The commission says the findings mean the Met's approach is 'possibly discriminatory' and suggests racial stereotyping is a significant factor behind the figures. It is refusing to rule out legal action against the worst offending forces.
Between October 2008 and November 2008, 5,295 white people were stopped compared to 4,925 black people. Based on population figures, this mean black people are 6.9 times more likely to be stopped than white people. 789 Asians were stopped.
It also found police forces are likelier to give more lenient reprimands and fines to white offenders even when offences or criminal history of the suspects are similar to those of a black or Asian man.
The commission says it will be writing to police forces with the most disproportionate ratios urging them to change their approach, arguing that those forces which apply a 'rule of law' approach, as opposed to an 'adversarial' one, had better relationships with black and ethnic communities, resulting in fewer arrests.
The EHRC's Simon Woolley# said: "There is little evidence to suggest targeting black people disproportionately with stop and search powers reduces crime. In fact, this report shows evidence that police forces, like Staffordshire and Cleveland, which have used fairer stop and search tactics have not only seen reductions in crime rates in line with overall trends, but have also increased public confidence in the police.
"It is unrealistic and unhelpful to demand policing should be perfect. However, police services should strive to work fairly and effectively while respecting basic human rights and discrimination law. Only then can they be said to be ‘good enough’.
"The Commission will be looking closely at this research and will be writing to police forces with the most concerning statistics to gain a better understanding of how they are meeting their obligations under the Race Relations Act. We cannot rule out taking legal action against some police forces."
The Met has defended its record, insisting it liaises with community leaders and residents' groups about the rationale behind its stop and searches, believing it is totally open about a tactic which it insists is vital in the battle to cut crime.
A spokesman said: "Openness and transparency is very important to us, and we are one of the few forces who publish our data on our Internet site. The community is encouraged to look at the figures and challenge their local boroughs about any concerns they may have.
"We take community leaders and key figures on operations as observers to see the tactics in action and welcome their feedback. We continually emphasise to officers that stop and search should be carried out tactfully, sensitively and professionally at all times, and there is targeted, specific training for all officers on the use of stop and search powers."