Maina Kiai said revelations about the activities of Kennedy, an undercover officer who was exposed in 2011 as a police source within environmental movements, as well as the cases of other undercover officers, were as damaging as the phone-hacking scandal which prompted the Leveson inquiry.
The UN special rapporteur said he was “deeply concerned” about the use within the UK of embedded undercover police officers in non-violent groups which exercise their democratic rights to protest and take peaceful direct action.
“The case of Mark Kennedy and other undercover officers is shocking as the groups in question were not engaged in criminal activities,” he told a news conference in central London.
“The duration of this infiltration, and the resultant trauma and suspicion it has caused, are unacceptable in a democracy.
“It is a clear violation of basic rights protected under the Human Rights Act.”