Edward Snowden has been granted permission to stay in Russia for another three years. It means the American whistleblower can now stay in Russia until the summer of 2017.

The former National Security Agency (NSA) worker lifted the lid on massive surveillance operations. He was originally granted asylum for 12 months, but that ran out last week.

His layer says he has now found a job in Russia, where he is working in the IT sector. The permit also gives him freedom to travel abroad.

Snowden (30) has previously claimed he "trained as a spy" and worked "undercover overseas" for intelligence agencies.

In an interview in May, he rejected claims he was merely a junior contractor, saying he worked "at all levels from the bottom on the ground, all the way to the top".

He has been charged in the US with espionage and was granted asylum by Russia in August 2013, after instigating a series of leaks on mass surveillance in America and around the world.

"I was trained as a spy in sort of the traditional sense of the word in that I lived and worked undercover overseas - pretending to work in a job that I'm not - and even being assigned a name that was not mine" he told NBC.

He said he had worked covertly as "a technical expert" for the Central Intelligence Agency (CIA) and the NSA, and as a trainer for the Defence Intelligence Agency.

"I don't work with people. I don't recruit agents. What I do is I put systems to work for the United States. And I've done that at all levels from, from the bottom on the ground all the way to the top" he said.

"So when they say I'm a low-level systems administrator, that I don't know what I'm talking about, I'd say it's somewhat misleading" he added.