The leak, reported late Sunday, follows a broader cyber campaign that also compromised data from the Ministry of Defense, the Home Office, the National Crime Agency (NCA) and the Crown Prosecution Service (CPS), according to The Times.
The latest breach also comes just days after hackers targeted the Department for Education (DfE), exposing more than 500,000 records.
Hackers exposed police officers’ force affiliations after breaching the Police National Legal Database (PNLD), an online legal resource used by Home Office police forces across the UK.
Authorities believe the cybercriminal group ExfilSquad was behind the attack, which is part of a series of recent breaches targeting Western institutions.
“I have worked in serious organized crime and put high-level criminals behind bars. For private information to be leaked about me is very disconcerting and puts officers at serious risk," said one member of staff whose details were leaked.
“In the past, I have been forced to move into safe houses and sell cars due to my job. Now I will have to keep my wits about me online and look out for anyone trying to get more serious information. It is not a good look.”
The DfE hack resulted in 607,000 pieces of data being published on the dark web and is believed to have been carried out for financial rather than ideological reasons.
The group said online: “Once your company’s data is posted here, it’s NEVER leaving the public eye, and it will be passed around the internet FOREVER. The payment we request of you is simply a rounding error compared to the litigation costs of your data leaking. Be smart and just pay.”
One source said most police officers have used the legal database at some point during their careers to carry out routine policing duties.
The database is used by police forces across England and Wales, where 145,550 full-time officers are employed.