The DNA records of about 850,000 people could be wiped from the U.K.'s national database after the European Union ruled it breached human rights.
The European Court of Human Rights decision on Thursday means that the DNA details and possibly fingerprints of people suspected of a crime, but later cleared, could be removed.
The court found that in keeping the DNA details of people suspected of a crime the "state had overstepped any acceptable margin of appreciation."
The case was brought by two Britons, Michael Marper and "S", who were cleared of crimes and challenged the government over their details being kept on the 4.5 million-strong police database.
A U.K. Home Office representative said the government has until March before it must take any action on the ruling.
Home Secretary Jacqui Smith expressed dissatisfaction with the verdict, saying in a statement: "DNA and fingerprinting is vital to the fight against crime, providing the police with more than 3,500 matches a month, and I am disappointed by the European Court of Human Rights' decision...The existing law will remain in place while we carefully consider the judgment."
Privacy pressure group NO2ID welcomed the decision with the organization's national coordinator Phil Booth describing it as a victory for liberty and privacy.
Nick Heath of ZDNet UKreported from London.