article: The previously unknown case will place fresh pressure on the force, which last year was forced to apologise to seven women who had similar relationships. The woman in the latest case told BBC Newsnight she was a victim of "psychological torture". The Met would neither confirm nor deny the identity of the undercover officer. The woman, who is being referred to by the pseudonym Andrea to protect her identity, was friends with a group of left-wing political activists, mostly in the Socialist Party, who are thought to have been the target for long-term infiltration by the Met. The Socialist Party is a democratic political group to the left of the Labour Party that rejects violence. On Monday, she started legal action against the Metropolitan Police over the relationship, which lasted from 2002 to 2004. A joint investigation by BBC Newsnight and The Guardian has unmasked Andrea's former partner, who was pretending to be a left-wing political activist. He used the cover name Carlo Neri. The BBC knows his real name but is not publishing it to protect his family. Mr Neri proposed to Andrea in 2003 and she accepted. He was welcomed into her family and her parents, who lived in Scotland, viewed him as a future son-in-law. Andrea told Newsnight that the deception she suffered meant she was the victim of "psychological torture" authorised by the police. When he was living with Andrea undercover in central London, from November 2002 to May 2004, Mr Neri was married with a child. He had a double life and needed to invent reasons to be away from the flat he and his wife shared in Maida Vale. He showed Andrea photographs of a boy and said it was his son from a previous relationship. He said that his former partner had moved to Cornwall with the boy and he wanted to re-establish contact. Full story on Newsnight on Monday 18 January at 22:30 on BBC Two "He was probably away from home for four or five nights every fortnight and that would be due to work trips and every other weekend he would go to Cornwall to see his child," Andrea said. "As far as I was concerned, I was going to spend my life with this man and his life was my life. Having that strong relationship with a child is a really important thing." In fact there were no access trips to Cornwall. The photographs were of his real son who lived with his wife less than 10 miles away. It was just part of his cover story. When he was living with Andrea in Maida Vale, Mr Neri liked to make himself useful to her friends in the Socialist Party. He said he was a locksmith. "He quite often said people could improve their security of where they lived and again that seemed at the time to be hugely helpful. With hindsight there's a different perspective really because there's a huge amount of people's locks that someone had access to," Andrea said. Why the undercovering policing inquiry matters The key participants
summary: An undercover Metropolitan Police officer proposed to an activist and lived with her for 18 months, the BBC has learned.