· Figures show Asian people bear brunt of use of power · Fears that tactic causes loss of confidence in police

Only one in every 400 stop and searches carried out under sweeping anti-terrorism laws leads to an arrest, official figures released yesterday reveal, triggering fresh pressure on the government and police over the controversial tactic.

Official government figures covering 2005/6, the first since the July 7 2005 bombings on London, show a big increase in the use of the power, with Asian people bearing the brunt. One force, City of London, carried out 6,846 stops of pedestrians and vehicles without finding enough evidence to justify a single arrest.

Stops under the Terrorism Act 2000 rely more on an officer's discretion than other powers to search, which require reasonable suspicion. The number of stops under terrorism laws in 2005/6 showed a 34% rise on the previous year to 44,543. Asians faced an increase of 84%, black people an increase of 51%, searches of "other" ethnic groups rose 36% and white people faced a 24% increase.

The biggest increases were in London, with the Metropolitan police carrying out more than half of all terrorism stop and searches and the City of London force 15%.

Experts believe anti-terrorism stop and searches have not led to a single person being caught who was later convicted of a terrorist offence.

Police say that even if this is the case the power is useful because it can be used to disrupt terrorist activity. Some senior officers have considered scaling back the use of the power or scrapping it, fearing it does more harm than good.

In the 44,543 stops in England and Wales, there were 105 arrests. Out of every 400 people stopped 399 were let go straight away.

Ben Bowling, professor of criminal justice at King's College London, said: "If these people arrested were in possession of bombs you might say that's fine, but I can't recall a case where that's happened.

"These powers are being used indiscriminately with a minimal result. The consequence of that is a loss in public confidence and a drop of support among those stopped without reason for the police."

The figures showed that the racial divide in stop and search aimed at stopping non-terrorist crime also became starker. Black people were seven times more likely to be stopped and searched by police.

The number of stop and searches carried out under the Police and Criminal Evidence Act, which legally require reasonable suspicion, hit their highest level in seven years. In 2005/6 police carried out 878,153, a 3.4% increase on the previous year, with drugs being the main reason given by officers for searches.

The figures also show police missing their targets for ethnic minority recruitment. Police managed a slight increase on the previous year to take the proportion to 3.7%, which is short of the 4% target.

While the proportion of full-time police officers is lower than the overall ethnic minority population, the percentage of special constables and police community support officers is considerably higher.

The number of racist incidents recorded by police rose 4%, to 60,407, though the government says this is only a fraction of those that occurred. Racially or religiously aggravated offences rose by 12% to 41,382.

A serving Met police superintendent, Ali Dizaei, who is also president-elect of the National Black Police Association, said: "The report debunks the myth that there is less stop and search by the police. In fact, there has been an increase over the year.

"It also shows the massive disproportionality which exists for black and Asian people being searched. The disproportionality will continue to shake the trust and confidence of black and Asian communities at a time where the police needs them on board."

A Home Office spokesperson said in a statement: "The government wholly supports the powers of stop and search and believes it to be a vital tool for police officers in preventing, detecting and reducing crime, whether it be street robbery, gun crime, drug-dealing or terrorism.

"The key to effective and fair use of stop and search is that it should be used in a targeted, intelligence-led way, with good grounds and based on accurate, up-to-date intelligence.

"Our aim is to ensure that officers have the confidence to use the powers effectively to tackle crime, whilst promoting confidence in their use amongst all members of the community."