Fugitive whistleblower Edward Snowden has reunited in Russia with his girlfriend, according to a documentary premiered in New York.

The two-hour documentary filmed by journalist Laura Poitras and named Citizenfour reveals that Snowden's girlfriend Lindsay Mills, a dancer, has been living with him since July.

They parted when Snowden left Hawaii for Hong Kong in May 2013.

The documentary, scheduled for a wider release on 24 October, shows the two cooking together in an apartment in Moscow, where Snowden was granted a three-year residency permit.

It was assumed that Snowden had deserted Mills, and that she had left Hawaii to stay with her parents in mainland US.

Since Snowden received international attention by leaking millions of documents about the massive surveillance practices by the US National Security Agency (NSA), Mills has remained silent, staying away from interviews.

After he was granted asylum in Russia, Snowden gave a number of interviews but he preferred not to talk about his personal life, and focused more on the wider debate about US surveillance.

"When the Guardian met Snowden in Moscow in July, Snowden suggested the relationship was more complex than the view constantly recycled in the media of a woman abandoned and hinted that the two were not in fact estranged," the newspaper writes.

"I hope people won't see this as a story about heroism. It's actually a story about what ordinary people can do in extraordinary circumstances," Snowden told the Guardian, commenting about the documentary.

Snowden attracted international attention after he leaked up to 1.7 million top secret documents about the NSA's surveillance programmes.

The Obama administration faced severe criticism across the globe as the documents revealed that the NSA had tapped telephone conversations and spied on the internet activities of prominent people, including German chancellor Angela Merkel and Brazilian president Dilma Rousseff.

Snowden is wanted by the US on charges of espionage and theft of government property.

Watch the trailer of the documentary below.