Britons of South Asian descent are far more likely to be detained in anti-terrorism raids than other ethnic groups - and more than half of all suspects arrested in terrorism cases since 2001 were freed without charge, a government study disclosed on Wednesday.
The report, which covers the period since the 9/11 attacks in the United States, is expected to reinforce the widespread feeling among British Muslims that they are being unfairly singled out by police, community leaders said.
Britain's Home Office said 1,471 people were arrested as suspected terrorists between September 2001 and March 2008 - but that less than 200 of them were eventually convicted on terrorism charges.
The report showed that around 13 percent of those arrested were convicted of terrorism, compared to 30 percent in other serious crimes.
Around 55 percent of all those arrested on suspected terrorism charges were released without charge. The Home Office said it did not have comparable data on how many people are arrested and released without charge for other crimes.