Police Scotland ‘bulk deleted’ fingerprints following an IT blunder which led to their irrecoverable loss, the Mail can disclose.

Biometrics Commissioner Dr Brian Plastow revealed rebooting a computer resulted in the prints being scrubbed.

The force is now understood to be assessing whether to advise Chief Constable Jo Farrell if the Information Commissioner’s Office (ICO) will have to be notified.

A report by Dr Plastow said his office had ‘heard some evidence of fingerprint records being bulk deleted by staff from the terminal in rare instances to reboot the terminal for use in the live environment resulting in the permanent loss of lawfully acquired fingerprints’.

It said this was not authorised Police Scotland practice and could result in several breaches of the Data Protection Act. Any accidentally or otherwise wrongly deleted data that cannot be recovered (if deemed high risk) would legally have to be reported to the ICO.

Dr Plastow said: ‘We will follow up on the recommendations in due course to satisfy ourselves that the necessary improvements have been achieved.’

The Commissioner also warned that a failure to fingerprint all arrested people could lead to ‘lost investigative opportunities, both now and in the future’.

He said prints can be run through databases within 20 seconds but Police Scotland do not fingerprint all suspects, meaning that ‘investigative opportunities’ are lost.

Dr Plastow, who recently called for all suspects to be fingerprinted, said the Criminal Procedure (Scotland) Act 1995 gives ‘authority in law for the police to fingerprint anyone who has been arrested regardless of whether they are charged’.

Dr Plastow told the Mail: ‘It is a regular occurrence for persons arrested for minor offences to have fingerprints taken in police custody which then produce a match to prints from an unsolved crime scene.

‘We include a case study in our recent fingerprint report where this happened and helped to solve a cold case murder in Scotland.’

His Majesty’s Inspectorate of Constabulary in Scotland said last year that Police Scotland officers were still using ink and paper to take prints in some parts of the country rather than using digital methods – a finding echoed by Dr Plastow.

Fingerprints have been used in police investigations in the UK for more than 120 years and are the most established form of biometric data.

In November 2025, Police Scotland held 831,014 fingerprint forms relating to 455,040 people on the UK law enforcement fingerprint database IDENT1.

It also held 1.1million forms ‘off database’ in a national collection of paper records.

It is understood the force has not made any referrals to the ICO so far in relation to the deleted prints, the number of which is believed to be in the tens rather than hundreds.

A Police Scotland spokesman said: ‘We are reviewing the recommendations from the [Biometrics Commissioner’s] assurance review and will take any action that is appropriate once this is complete.’