Britain's information regulator said on Tuesday it had reprimanded two police forces for recording over 200,000 phone calls, likelywith victims, witnesses and perpetrators of suspected crimes, without people's knowledge.
The Information Commissioner's Office (ICO) said the reprimand was issued to Surrey Police and Sussex Police, following the roll-out of an app in 2016 that recorded phone conversations and unlawfully captured personal data.
The police forces did not immediately respond to Reuters' requests for a comment.
The ICO said it became aware in 2020 that staff members across both police forces had access to the app which recorded all incoming and outgoing phone calls.
The app was downloaded by 1,015 staff members and more than 200,000 recordings of phone conversations were automatically saved, the regulator said.
"We can only estimate the huge amount of personal data collected during these conversations, including highly sensitive information relating to suspected crimes," ICO Deputy Commissioner for Regulatory Supervision Stephen Bonner said in the statement.
"This case should be a lesson learned to any organisation planning to introduce an app, product or service that uses people's personal data. Organisations must consider people's data protection rights and implement data protection principles from the very start."