Several undercover police officers who started sexual relationships with women in groups they infiltrated will not be prosecuted.
The Crown Prosecution Service said there was "insufficient evidence" to charge the officers for offences including rape and indecent assault.
In a statement the CPS said: "Having carefully considered all the available evidence we have determined that there is insufficient evidence for a realistic prospect of conviction for any offences against any of the officers."
Scotland Yard said it will now consider if misconduct proceedings are appropriate.
Five officers who allegedly had relationships with women activists, which lasted from seven months to nine years, have now been publicly named.
They are Jim Boyling, Bob Lambert, John Dines, Mark Cassidy and Mark Kennedy, who posed as long-haired drop out Mark "Flash" Stone.
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Remarkably mild night for March