Senior police officers have warned that anti-terrorism laws could result in discrimination against Muslims.

Metropolitan Police assistant commissioner Tarique Ghaffur said tough legislation introduced in the wake of the September 11 and July 7 terror attacks could "criminalise" minority groups.

Speaking at a conference hosted by the National Black Police Association, he was also expected to call for a judicial investigation into the causes of the "anger and resentment" felt by young British Muslims which resulted in the London  bombings.

"Not only has anti-terrorism and security legislation been tightened across many European countries with the effect of indirectly discriminating against Muslims, but other equally unwanted practices have also emerged, including 'passenger profiling' as well as increased stop and search and arrest under terrorism legislation," Ghaffur warned.

He added that the use of stop and searching power tended "to be based more on physical appearance than being intelligence-led".

"There is a very real danger that the counter-terrorism label is also being used by other law enforcement agencies to the effect that there is a real risk of criminalising minority communities," he said.

"The impact of this will be that just at the time we need the confidence and trust of these communities, they may retreat inside themselves."

Britain's most senior Asian police officer was also set to outline how racism in the police has affected his own career.

Chief superintendent Ali Dizaei of the Metropolitan Police gave his backing to the warning.

"What's clearly happening and what we have been told is that the Muslim  community, particularly the young Muslim community, are increasingly concerned about what's happening in the Middle East," he told BBC Radio 4's Today programme.

"They're increasingly concerned about the disproportionate impact of  anti-terror laws, not just by the police but by other law enforcement agencies."

Keith Jarrett, chairman of the National Black Police Association, also expressed concern at police racism.

"The majority of the police service are decent, hard-working people who are not bigoted, but the people who are bigoted will always be bigoted," he told Sky News.

"But I know routinely black youths are stopped simply because they're black.

"Senior officers in the police service in London have said to junior officers, 'You will go out and you will stop black youths wearing these clothes and in this age group because they are the ones that are committing robberies.' Now that is institutionally racist."