Human rights activists in UK are mounting a sustained campaign for removal of DNA records of innocent people from the national database as a Tory MP wins his own battle with the Scotland Yard.
Mr Damian Green, the shadow immigration minister, demanded that his details be erased after no charges were brought against him following his arrest over Whitehall leaks last year.
The MP's fingerprints and DNA were taken after he was arrested in November last year as part of a police investigation into a series of leaks from the Home Office.
Officers raided his home and Commons office and questioned him for 11 hours. The affair caused a political storm and resulted in a Ł1 million, five-month investigation.
But in April, the Crown Prosecution Service decided not to charge Mr Green or Christopher Galley, a Home Office civil servant who passed him information. It took a further four months for the Metropolitan Police to agree to delete his DNA.
In a letter to the MP, the force said his case could be treated as "exceptional" and his records would be deleted.
The decision by Scotland Yard is likely to lead to fresh demands for the DNA of all innocent people to be removed. Ministers are under pressure to delete the records of at least 850,000 people who have never been convicted of an offence.
Mr Green said: "I am delighted that the Metropolitan Police has recognised that keeping the DNA records of someone who should not have been arrested in the first place is wrong. This is a small but significant victory for freedom.
"But this is only a first step. I want every innocent person who has been arrested and whose records are being wrongly held to be treated the same as me."
Human rights campaigners said Mr Green's case highlighted the injustice of the system, in which requests from public figures were more likely to succeed than those of ordinary citizens.
Shami Chakrabarti, director of Liberty, said: "The removal of Mr Green's DNA from the database is a glaring admission of a guilty policy.
"Parliamentary duty was insufficient protection against a raid on his home and office, but now while millions of other innocents give up control of their most intimate information, the MP is more innocent than others.
"Fundamental rights are not tables in fashionable eateries - they shouldn't depend on a Who's Who entry."
Since 2001, the police have had the right to retain the DNA records of innocent people. But there is no formal process for removal.
In 2006-07, just 488 requests for a DNA profile to be destroyed were successful in England and Wales while just 348 succeeded in the previous year. Many of those were believed to be from witnesses rather than suspects.
In contrast, more than 700,000 profiles have been added to the database every year since 2005. There are now 5.30 million profiles on the system, making it the largest of its kind in the world.
The Home Office launched a review of the database after the European Court of Human Rights ruled last year that a blanket policy of retaining profiles of innocent people indefinitely was illegal.
But under current proposals, the DNA profiles of innocent people would remain on the database for up to 12 years depending on the seriousness of the offence they were arrested for.
Earlier this month, a leaked letter from the Association of Chief Police Officers said forces were warned against starting to destroy the samples of innocent people.