Film director Oliver Stone has branded the popular gaming app Pokemon Go a "new level of invasion" of privacy that could lead to "totalitarianism".

The American reportedly voiced concerns over the game as he promoted his new movie about NSA whistleblower Edward Snowden at Comic Con International.

Stone, 69, said companies were carrying out "surveillance capitalism" by monitoring people's behaviour, after he was asked about security concerns associated with Pokemon Go.

According to Time magazine, he told the Comic Con audience in San Diego: "It's not funny. What's happening is a new level of invasion.

"The profits are enormous here for places like Google. They've invested a huge amount of money in data mining-what you are buying, what you like, your behaviour.

"It's what some people call surveillance capitalism."

He added: "You'll see a new form of, frankly, a robot society. It's what they call totalitarianism."

Pokemon Go, which is free to download, has faced criticism over claims it could access a player's entire Google account, including email and passwords.

The app's makers, Niantic, insisted the move was unintentional and reassured users that it was not collecting any exceptional data.

Stone was joined at the Comic Con panel by Joseph Gordon-Levitt, who plays Edward Snowden in the upcoming film and visited the former NSA analyst in Moscow where he is in exile.

Stone, who won a Best Director Oscar for Platoon, claimed every major movie studio turned down his new film, forcing him to find finance in France and Germany.

Snowden is due to be released in America on September 16. A UK release date has yet to be confirmed.