Oliver Stone will write and direct a film about Edward Snowden, one of two high-profile films in the works about the US National Security Agency leaker.

Stone announced on Monday that he plans to adapt The Snowden Files: The Inside Story of the World's Most Wanted Man, a book by Guardian journalist Luke Harding. The project pairs one of cinema's most controversial directors with one of the most explosive news events in recent years - one that is ongoing.

"This is one of the greatest stories of our time," Stone said in a statement. He added that making such a film is "a real challenge".

"I'm glad to have the Guardian working with us," he said, according to Russia Today.

"The story of Edward Snowden is truly extraordinary, and the unprecedented revelations he brought to light have forever transformed our understanding of - and relationship with - government and technology," said Guardian Editor-In-Chief Alan Rusbridger. "We're delighted to be working with Oliver Stone and Moritz Borman on the film."

He will have some deep-pocketed competition. Last month, Sony Pictures bought the big-screen rights to Glenn Greenwald's No Place to Hide: Edward Snowden, the NSA and the US Surveillance State. The film is being produced by James Bond producers Barbara Broccoli and Michael G. Wilson.

Stone has advocated for the former NSA contract systems analyst, who is living in Russia on a temporary grant of asylum after leaking massive amounts of NSA documents to the media.

Snowden: I want to go home, but can't

"To me, Snowden is a hero because he revealed secrets that we should all know, that the United States has repeatedly violated the Fourth Amendment," Stone said in a news conference at the Karlovy Vary Film Festival in the Czech Republic.

The film adaptation of The Snowden Files is expected to get a big boost with the addition of Stone to the project. If it's received anything like Harding's book has been, however, then the production team working on that movie might have their work cut out for them: Upon release of The Snowden Files earlier this year, Greenwald and Snowden ally WikiLeaks both raised questions about Harding's work, according to Russia Today.

"The Inside Story of Edward Snowden, by Someone Who Never Met or Spoke With Edward Snowden", Greenwald referred to the Harding's book in a tweet he sent in February. WikiLeaks, who has been among the most adamant supporters of both Snowden and Greenwald in the past, called Harding's book a "hack job" composed of "unattributed rewrites of press reports".

AP-Reuters