Police won a crucial appeal today against an Information Tribunal ruling that data on old minor convictions must be deleted from police computers.
If the ruling by the Court of Appeal in a test case relating to the convictions of five people had gone against the police, it would probably have resulted in the deletion of around a million convictions.
Three judges ruled that retaining information for police operational needs in the fight against crime was far easier to justify than actually disclosing the information to others.
"If the police say rationally and reasonably that convictions, however old or minor, have a value in the work that they do, that should, in effect, be the end of the matter," said Lord Justice Waller, sitting with Lords Justices Carnwath and Hughes.
The judges allowed an appeal by the Chief Constables of Humberside, Staffordshire, Northumbria, West Midlands and Greater Manchester Police.
The five convicted people who had contested the case were refused permission to appeal to the Supreme Court.
Under the Data Protection Act, information must be relevant, up to date and not excessive.
The five people at the centre of the case lodged complaints after their records showed up in checks when they applied for jobs.
One of the cases was a record held by Humberside Police about the theft of a 99p packet of meat in 1984. The person involved, who was under 18 at the time, was fined £15.
Another, held by West Midlands Police, referred to a theft which took place more than 25 years ago, for which the individual was fined £25.
A third, held by Staffordshire Police, related to someone under 14 who was cautioned for a minor assault.
Under current police policy, criminal records can remain on the police national computer for up to 100 years.
The Association of Chief Police Officers (Acpo) and the five chief constables welcomed the decision of the Court of Appeal.
Ian Readhead, Acpo director of information, said: "This decision provides valuable clarification on the retention of criminal conviction data on the Police National Computer.
"While this particular case involved five individuals, the ramifications of losing the appeal were potentially huge.
"This data assists police officers in their work in preventing crime and protecting the public and the loss of such valuable information would have been detrimental to that.
"Although principally used for police purposes, these records are also critical to the courts, the Criminal Records Bureau, the Independent Safeguarding Agency, the Crown Prosecution Service and the Home Office, who all supported this appeal."
Mr Readhead said Acpo also welcomed the opportunity to participate in a review of the criminal conviction retention policy to be carried out by an Independent Advisor at the request of the Home Secretary.