Former intelligence contractor and NSA whistleblower Edward Snowden told the BBC's Panorama last night that the UK intelligence centre GCHQ has the power to hack phones without their owners’ knowledge.

He told the programme that smartphone users are able to do "very little" to prevent security services having "total control" over their devices.

The set of tools is, according to Snowden, called “Smurf Suite” and there are a number of functions:

“Dreamy Smurf” : lets the phone be powered on and off

: lets the phone be powered on and off “Nosey Smurf” :lets spies turn the microphone on and listen in on users, even if the phone itself is turned off

:lets spies turn the microphone on and listen in on users, even if the phone itself is turned off "Tracker Smurf" :a geo-location tool which allows [GCHQ] to follow you with a greater precision than you would get from the typical triangulation of cellphone towers.

:a geo-location tool which allows [GCHQ] to follow you with a greater precision than you would get from the typical triangulation of cellphone towers. “Paranoid Smurf”: hides the fact that it has taken control of the phone. The tool will stop people from recognising that the phone has been tampered with if it is taken in for a service, for instance.

Snowden told Panorama:

GCHQ is, for almost [all] intents and purposes, a subsidiary of the NSA. They provide technology, they provide tasking and direction as to what they should go after. And in exchange GCHQ provides access to communications that are collected in the UK.

A spokesperson for the UK government told the BBC that it does not comment on intelligence matters but that its spying work is executed within a “strict legal and policy framework”.

Snowden also told the programme, his first interview with the BBC, that he would be prepared to accept jail time in the US in order to return home.

I’ve volunteered to go to prison with the government many times. What I won’t do is I won’t serve as a deterrent to people trying to do the right thing in difficult situations.

On the same programme, former NSA boss Michael Hayden told the BBC:

If you’re asking me my opinion, he’s going to die in Moscow. He’s not coming home.