Police guidelines allowing forces to retain the fingerprints and DNA samples of innocent people are unlawful, a panel of leading British judges has ruled.
The ruling was made by the Supreme Court in London nearly three years after the European Court of Human Rights reached a similar conclusion.
Judges said Government plans for changes to the law were already in the pipeline.
The 1984 Police and Criminal Evidence Act required the destruction of samples and fingerprints "taken from a person in connection with the investigation of an offence if he was cleared", said judges.
But the law changed in 2001 and gave police the discretion to retain samples "after they have fulfilled the purposes for which they were taken".
The Association of Chief Police Officers (Acpo) had gone on to issue guidelines saying "data should be destroyed only in exceptional cases", said judges.
A panel of seven Supreme Court justices has now concluded, by a five to two majority, that those Acpo guidelines were unlawful because they did not comply with European human rights legislation on rights to privacy.
The Supreme Court - the highest court in England - made the ruling in allowing appeals by two men who said police in London had unfairly retained their fingerprints and DNA samples.
Judges at the European Court of Human Rights made a similar ruling in December 2008 after allowing appeals by two men from Sheffield, who also said South Yorkshire Police had unfairly retained DNA samples.
European judges were asked to rule on the Sheffield cases after judges at the House of Lords - then England's highest court - rejected appeals, saying retention of DNA samples did not breach European human rights privacy laws.