Human rights organisation Amnesty International is calling for an inquiry following the Government Communications Headquarters (GCHQ) spy agency's admission to using its resources to spy on them.
The Investigatory Powers Tribunal's (IPT) earlier report on GCHQ's spying activities, which had showed that that two foreign organisations - the Egyptian Initiative for Personal Rights and the South African Legal Resources Centre - are GCHQ's targets, have been revised today, stating that EIPR was never targeted, but Amnesty International was.
The IPT has admitted it made a mistake in its earlier findings.
The documents leaked by former NSA whistleblower Edward Snowden led to the earlier investigation.
"After 18 months of litigation and all the denials and subterfuge that entailed, we now have confirmation that we were in fact subjected to UK government mass surveillance," Amnesty International secretary general Salil Shetty said. "The revelation that the UK government has been spying on Amnesty International highlights the gross inadequacies in the UK's surveillance legislation. If they hadn't stored our communications for longer than they were allowed to, we would never even have known. What's worse, this would have been considered perfectly lawful."
IPT's email to Amnesty International does not identify the reason for why it was targeted for surveillance activities, nor what was done with any information obtained from the surveillance, the human rights organisation has claimed.
Neither the government nor GCHQ has yet issued a statement on the matter.