Britain's information regulator said on Tuesday it had formally reprimanded two police forces for recording more than 200,000 phone calls, likely with 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 rollout of an app which recorded phone conversations and unlawfully captured personal data.
The regulator said it became aware in 2020 that staff members across both police forces had access to the app, first made available in 2016, which recorded all incoming and outgoing phone calls.
The ICO said the app was downloaded by 1,015 staff members and more than 200,000 recordings of phone conversations were automatically saved.
"People have the right to expect that when they speak to a police officer, the information they disclose is handled responsibly," ICO Deputy Commissioner for Regulatory Supervision Stephen Bonner said.
"We can only estimate the huge amount of personal data collected during these conversations, including highly sensitive information relating to suspected crimes."
In a joint statement, the police forces said they had new governance in place to ensure all new apps are compliant with legislation before being made available.
"This case exposed a lack of governance around use of this digital application, and this is regrettable," Temporary Assistant Chief Constable Fiona Macpherson said. "As soon as the error was reported, we took urgent action to ensure that this did not happen again."
The app has been withdrawn from use and the recordings, other than those considered to be evidential material, have been destroyed, the ICO said.
The ICO said it was issuing the reprimand instead of a 1 million pound fine as part of trial aimed at avoiding handing out fines which would impact budgets for vital public services.
(Reporting by Muvija M and Sachin RavikumarEditing by William Schomberg, Paul Sandle and Kylie MacLellan)