NSA whistleblower Edward Snowden has accused Russia of going too far with its online monitoring of its citizens, "in ways that are completely unnecessary, costly and corrosive to individual and collective rights".

His criticism came despite the fact that he has been living in the country since he fled the US in 2013 with thousands of classified documents that the revealed the surveillance capabilities of the US National Security Agency (NSA).

While his critical tweets about his new homeland have led to "a lot of people who care" about him, telling him "to shut up", he admitted he "can't fix the human rights situation in Russia".

Realistically he said his "priority is to fix my own country first," the 33-year-old told The Financial Times. "That's the one to which I owe the greatest loyalty," he said. "But though the chances are it will make no difference, maybe it'll help."

His criticism was not reserved for Russia however, as he said that in recent years surveillance laws "have gotten worse in some countries. France has gone very far… In Britain, there's an authoritarian trend".

He added: "We typically don't reorder the operation of a free society for the convenience of the police – because that is the definition of a police state. And yet some spies and officials are trying to persuade us that we should".

Snowden, who faces espionage charges should he return to the US, for which he could serve up to 30 years in prison, hit the headlines when fled his homeland for Hong Kong, having revealed extensive internet and phone surveillance by US intelligence.

After the US filed charges and asked local authorities to extradite him, he left Hong Kong for Moscow, with the intention of seeking asylum in Ecuador. However, he has since remained in Russia, where he lives in a secret location.

That dramatic time in his life has recently been dramatised by Oliver Stone, in the film Snowden with Joseph Gordon-Levitt playing the lead.

Despite calls for him to be extradited and prosecuted in the US, earlier this year lawyers said they were hoping to secure a presidential pardon for him before Barack Obama leaves office.

"We're going to make a very strong case between now and the end of this administration that this is one of those rare cases for which the pardon power exists," his principal legal adviser Ben Wizner told New York Magazine in July.

"It's not for when somebody didn't break the law. It's for when they did and there are extraordinary reasons for not enforcing the law against the person."