Actor Joseph Gordon-Levitt has called for Edward Snowden to be pardoned before US President Barack Obama leaves office.
The actor, who portrays the hacker in director Oliver Stone's new biopic, met him in Russia before filming began and said he knows Snowden would love to return home to the US.
He told the Press Association: "I would love it if he would get pardoned, I would think that was the right thing to do and I would hope that Barack Obama, as someone who has generally really stood up for what the constitution says, I would hope he would pardon Snowden.
"That would send the right signal that the American government respects the constitution. I don't know if he can do that, I hope he does.
"I know Ed would like to come home, I know his family would like him to come home. I think he cares less about his personal life and his personal comfort than he does about these issues though, he made that clear."
The film Snowden tells the story of the hacker, from his first contact with the NSA to the meetings he had with journalists in a Hong Kong hotel room, and Gordon-Levitt said the movie feels even more urgent since the election of Donald Trump.
He said: "I have spoken to people who supported me doing this movie and were like, 'I get what this is about, government mass surveillance. Yeah, that does go against the constitution, that is probably not right. I can't say I'm that concerned about it', and now those same people are like, 'That is really scary that our government can conduct that kind of mass surveillance'.
"If those tools are used with only pure intentions then okay, but if they are not then it starts to get scary."
The actor, who struck up a friendship with the former NSA contractor during their meetings in Moscow, said he hopes the film starts a conversation about privacy and surveillance.
"Meeting him really humanised him, which is the idea of this movie. The funny thing is he's always trying to take the attention off himself personally and put the attention on the causes he's fighting for, but I'm an actor playing him in a movie, so I was paying attention to personal details - how does he sit, how does he talk or walk, how does he shake my hand, because ultimately the point of this movie is to be an entertaining drama, to be a fun night at the cinema.
"There are other works of journalism if you want a more comprehensive piece about this stuff. This is just to get the conversation started."
Another conversation the actor would love to have is about a reboot of 1990s sitcom 3rd Rock From The Sun, the show that gave him his big break and that also featured The Crown star John Lithgow.
He said: "It could be Edward Snowden and Winston Churchill because John Lithgow is playing Winston Churchill right now.
"I would love to. I love all those folks and would love to see them. I do see them but would love to be making comedy with them. Snowden and The Crown and Third Rock From The Sun."