Human rights group says it is 'highly likely' its emails and phone calls have been intercepted by British intelligence

The human rights group Amnesty International has announces that it is taking legal action against the UK government over concerns its communications have been illegally accessed by UK intelligence services.

In the latest of a series of legal challenges sparked by the revelations based on documents released by the whistleblower Edward Snowden, Amnesty said it was "highly likely" its emails and phone calls have been intercepted.

Michael Bochenek, director of law and policy for the human rights group, said: "As a global organisation working on many sensitive issues that would be of particular interest to security services in the US and UK, we are deeply troubled by the prospect that the communications of our staff may have been intercepted."

The latest challenge follows revelations that GCHQ and its US counterpart, the National Security Agency (NSA), have developed capabilities to undertake industrial-scale surveillance of the web and mobile phone networks by trawling the servers of internet companies and collecting raw data from the undersea cables that carry web traffic. Two of the programmes, Prism and Tempora, can sweep up vast amounts of private data, which is shared between the two countries.

The scale of surveillance capabilities has led to widespread concern in Europe and the US about the ability of the UK and US security services to gather online communications. There are three legal challenges under way in the UK involving several groups including Liberty, Privacy International and Big Brother Watch.

Amnesty said that given the global and often highly sensitive nature of its work, it was "highly likely" the organisation's communications have been intercepted unlawfully by intelligence services on both sides of the Atlantic.

It has issued a claim at the Investigatory Powers Tribunal (IPT) arguing that the interception of its communications would be in breach of article 8 (right to privacy) and article 10 (right to freedom of expression) of the Human Rights Act.

"We regularly receive sensitive information from sources in situations that mean their co-operation with Amnesty could present a real risk to their safety and the safety of their family," said Bochenek. "Any prospect that this type of communication is being intercepted by the US and UK through their mass surveillance programmes raises substantive concerns and presents a real threat to the effectiveness of Amnesty International's work."

The IPT reviews complaints about the conduct of the UK's intelligence agencies, but critics say it is secretive and unregulated. Amnesty has asked the IPT hold a public hearing into its claims about surveillance. "In the face of such secret and extensive programmes of mass surveillance the current legal framework governing surveillance in the UK is woefully inadequate.

"It would be a ridiculous irony if the investigation into surveillance that has been carried out in secret was itself secret." © Guardian News and Media 2013