Kent Police has been fined £100,000 after confidential information, including police interview tapes, was found in a former police station.
The sensitive information, including records dating back to the 1980s, was thought to have been left when the site in Gravesend was vacated in July 2009.
It was discovered by an officer visiting a business owner on 27 November 2012 on an unrelated matter.
The fine was levied by the Information Commissioner’s Office (ICO).
ICO head of enforcement Stephen Eckersley said the tapes and files included “extremely sensitive and confidential information relating to individuals, many of whom had been involved in serious and violent crimes.
“If this information had fallen into the wrong hands, the impact on people’s lives would have been enormous and damaging.”
‘Lack of guidance’
The business owner told police he had found the pile of tapes bearing the Kent Police logo in the basement of the old police station after purchasing the site two months earlier.
He said he had been planning to watch them for entertainment.
The next day, the force visited the site and recovered hundreds of additional documents and evidence tapes.
These included recorded interviews with informants, crime victims and individuals who had subsequently been convicted.
Some of the documents also related to police staff.
An inquiry by the ICO found Kent Police had “no guidance or procedures in place to make sure personal information was securely removed from the former premises”.
It said the problem was made worse due to an apparent breakdown in communications between various departments involved in the move.
Kent Police said it had co-operated fully with the ICO and accepted the findings of its investigation.
In a statement, it said it was “unacceptable for police property to have been left at the site” and it had since reviewed its policies and implemented new procedures when vacating police premises.
It added that no sensitive information “was lost or further disseminated” following the incident.