Nearly 12,000 people over the past five years were wrongly branded criminals due to inaccurate record checks, leading to £1.9 million in redress, campaigners have revealed.
The figures, published by privacy and civil liberties campaign group Big Brother Watch after a Freedom of Information request, showed the most common errors involved information being disclosed by local police forces or the police national computer.
In 3,519 cases, the wrong person's entry on the police national computer was disclosed, BB Watch said.
The figures were obtained from the Criminal Records Bureau (CRB), which recently merged with the Independent Safeguarding Authority to form the Disclosure and Barring Service (DBS).
According to the CRB's annual report in July, 4.1 million checks were carried out in 2011.
BB Watch director Nick Pickles said: "Every error has the potential to ruin someone's reputation and career. The fact that thousands of cases have involved information held by local police forces, often never tested in court, shows how dangerous it is to create a culture of safety by database."
He added: "The police hold a vast amount of information, from photographs to written notes, and the way forward must be to bring this murky system out into the open and ensure that only information that is absolutely necessary is held."
The DBS was not immediately available for comment.
BB Watch requested the number of disputed CRB disclosures upheld in favour of the applicant between August 2007 and August this year. The upheld disputes fell under the Department for Education, Independent Safeguarding Authority and the Criminal Records Bureau.
But the highest volume of upheld disputes were as a result of "local police force information disclosed by the chief officer", the police national computer identification number not belonging to the applicant and the police national computer information being inaccurate.