NSA had access to UK citizens mobile and email details from 2007

Edward Snowden's latest leaks reveal that the US may have attempted to spy on UK citizens without the government's approval

The latest leaks from whistleblower Edward Snowden suggest that the US National Security Agency (NSA) kept the mobile phone numbers and email addresses of UK citizens who were not suspected of any criminal activity.

The reports, from Channel 4 News and the Guardian, said that rules that forbid the NSA from holding onto such data were modified in 2007 to enable it to do so. From 2007 onwards, the US was allowed to keep the mobile phone, fax numbers, emails and IP addresses of innocent Britons and analyse them.

The analysis included "contact chaining", for which the agency can examine the communications that a person has, as well as those communications of a friend of a friend of a friend.

Back in 2004, an agreement was made for the US to be able to keep hold of UK landline numbers, and use their systems to analyse them.

Britain and America had originally signed an agreement to share intelligence in 1946, and this was later extended to Australia, New Zealand and Canada, and was labelled the "five eyes" agreement.

A draft memo written by a senior officer in the NSA in 2005 suggested that the US would spy on British citizens without the UK's agreement.

It is not clear whether that proposal was acted on.

The US and UK authorities have so far declined to clarify what the UK got in return for the 2004 and 2007 agreements, and what happened to the 2005 draft memo.