"At least 20 of the undercover officers deceived women into intimate, sexual relationships.

The women had no idea that they were having relationships with men who were police spies. Some of the undercover officers had relationships with more than one woman during their undercover missions.

After the existence of the covert operation began to be exposed in 2010, the women grouped together and successfully took legal action against the police. So far, the police have paid compensation to at least 12 women who were deceived by the undercover officers."

"

https://www.bbc.co.uk/news/magazine-29743857

Trying to remember the name of the book it is covered in, too

Edit: Book was "Undercover: The True Story of Britain's Secret Police" iirc