Guardian is reporting that the Met allowed one of its officers to lie before a court about his identity in order to maintain his cover:
Police accused of allowing undercover officers to lie in court
False evidence claim arises from papers suggesting undercover officer Jim Boyling hid identity when prosecuted over protest:
Documents seen by the Guardian suggest that an undercover officer concealed his true identity from a court when he was prosecuted alongside a group of protesters for occupying a government office during a demonstration.
From the moment he was arrested, he gave a false name and occupation, maintaining this fiction throughout the entire prosecution, even when he gave evidence under oath to barristers. The officer, Jim Boyling, and his police handlers never revealed to the activists who stood alongside him in court that he was actually an undercover policeman who had penetrated their campaign months earlier under a fake identity.