Two West Midlands police forces may have to delete thousands of old criminal records from the national database after losing an appeal against and Information Commission ruling.
The Information Tribunal dismissed appeals from five police forces - including the West Midlands and Staffordshire forces - who were ordered to delete old criminal convictions from the Police National Computer.
The tribunal ruled that keeping the records was in breach of the Data Protection Act, which says personal information should not be kept for longer than necessary.
Police fear the ruling could have "far-reaching implications" for the holding of data. It could open the door to thousands of people convicted of minor offences when young to apply to have their criminal record removed. Under current policy, criminal records remain on the computer for up to 100 years.
One record held by West Midlands Police referred to a theft which took place more than 25 years ago, for which the individual was fined £25.
Another record held by Staffordshire Police related to someone under 14 who was cautioned for a minor assault.
The other records were held by the police forces of Humberside, Northumbria and Greater Manchester.
The tribunal upheld the ruling of the Information Commissioner's Office (ICO) in November that the holding of the records did not comply with the Data Protection Act.
The Act says personal information must be relevant, up-to-date, and not excessive.