Seven women who were deceived into "abusive, deceitful and manipulative" relationships with undercover police officers have won an extraordinary apology and substantial payouts from Scotland Yard.
Following a four-year legal battle, the Metropolitan Police announced it had reached a settlement with the women over civil claims relating to the "totally unacceptable" behaviour of officers working for two now defunct units.
The UK's largest force acknowledged that the relationships were a violation of the claimants' human rights, an abuse of police power and caused "significant trauma".
Assistant Commissioner Martin Hewitt apologised "unreservedly" on behalf of the Met, saying the relationships should never have developed and the women were "deceived pure and simple".
He added: "I am aware that money alone cannot compensate the loss of time, their hurt or the feelings of abuse caused by these relationships."
The details of the financial settlements are being kept secret - but in a statement, the women described them as "substantial".
They said: "Although no amount of 'sorry', or financial compensation, can make up for what we and others have endured, we are pleased the police have been forced to acknowledge the abusive nature of these relationships and that they should never happen."
They said the relationships lasted for as long as nine years.
One of the women told how she believed an undercover officer was "one of my closest friends and companions" for seven years, adding that the discovery of his true identity has been "devastating".
The apology and payouts centre on the conduct of officers working for the Special Demonstration Squad (SDS), an undercover unit within Special Branch that existed until 2008, and for the National Public Order Intelligence Unit (NPOIU), which was operational until 2011.
Some entered into long-term sexual relationships with women after going undercover in order to infiltrate protest groups.
Mr Hewitt said: "Relationships like these should never have happened. They were wrong and were a gross violation of personal dignity and integrity."
The Met's statement also said that:
:: None of the women with whom the officers had a relationship "brought it on themselves", adding: "They were deceived pure and simple."
:: That the relationships and the subsequent trauma left the women "at risk of further abuse and deception by these officers after the deployment had ended".
:: Whether or not genuine feelings were involved on the part of any officers is "entirely irrelevant and does not make the conduct acceptable".
Scotland Yard refused to identify the former undercover officers at the centre of the settlement, but they have been named in reports as Bob Lambert, Jim Boyling, Mark Kennedy, Mark Jenner and John Dines.
A number of investigations are being carried out into undercover policing, including a judge-led inquiry that opened earlier this year.
Mr Hewitt said it is a "lawful and important tactic", but it "must never be abused".
Last year, four former officers from the SDS who were accused of sleeping with women they were spying on were told they would face no criminal charges for their actions.
Set up in 1968, the mysterious unit has been the focus of intense controversy in recent years.
The force admitted in January that the identities of dead children aged up to 17 were used by officers, while a review found the squad spied on the family of murdered teenager Stephen Lawrence.