AMNESTY International demanded yesterday that David Cameron launch a full inquiry into allegations that the security services spied on the correspondence of human rights organisations.

The Investigatory ­Powers Tribunal (IPT), which oversees surveillance matters, had announced that the British state has been intercepting, accessing and storing Amnesty communications, but is yet to explain itself.

Amnesty secretary-general Salil Shetty and Amnesty UK director Kate Allen warned that the confirmation that the state had been spying on the communications of non-governmental organisations sent a “chilling message to human rights organisations and charities in the UK and abroad.”

Mr Shetty said: “This revelation makes it vividly clear that mass surveillance has gone too far. We must finally have proper checks and balances.”

Ms Allen added: “It’s absolutely shocking that Amnesty International’s private correspondence was deemed fair game for UK spooks, who have clearly lost all sense of what is proportionate or appropriate.”