Oscar-winner Kevin Macdonald's leap from Glasgow to Guantanamo Bay

French-Algerian actor Tahar Rahim plays Mohamedou Ould Slahi, the author of the prison memoirs

A lockdown premier for Oscar-winning director Kevin MacDonald's new film is fitting for a drama centred on a prisoner.

The filmmaker from Glasgow is telling the true story of a man detained in Guantanamo Bay without charge for 14 years.

The memoir had to be smuggled out of the notorious jail via its author's lawyer.

But the book has now become a major movie starring Jodie Foster, Tahir Rahim, and Benedict Cumberbatch.

And Kevin MacDonald has made a virtual return to his hometown as The Mauritanian gets its UK premier at the Glasgow Film Festival.

The online event will show the feature, which has already been nominated at this weekend's Golden Globes, for the first time.

The Mauritanian is based on the memoirs of Mohamedou Ould Slahi, who spent 14 years in Guantanamo Bay, suspected of involvement in the 9/11 attack on the Twin Towers.

Benedict Cumberbatch's company sent the book, Guantanamo Diary, to MacDonald, who is known for The Last King of Scotland, How I Live Now and State of Play.

The Mauritanian star Tahar Rahim has recently enjoyed success in BBC drama The Serpent

He was urged to speak to its author, who had smuggled the transcript out of Guantanamo via his lawyer, and eventually made the video call to Slahi in Mauritania in 2017, a year after he had been released.

"I had this most amazing Skype call with him where he just surprised me so much." says MacDonald in an interview with BBC Scotland's The Nine. "First of all he just called me 'bro'.

"He speaks like a 17-year-old American because he's learnt his English from all his guards who are all, you know, 19-year-old Americans.

"He's full of life, full of humour, full of warmth, and has managed to forgive the people who mistreated him for so long.

"And I thought this is a character I want to make a film out of."

Slahi's lawyer Nancy Hollander, played by Jodie Foster, was determined the film should be be made

The lead role is played by Tahar Rahim, the French-Algerian actor who has recently won plaudits for his starring role in the BBC drama The Serpent.

The other main characters are the lawyers involved in Slahi's case - Nancy Hollander who defended him and Lt Col Stuart Couch for the prosecution.

"[Hollander] and Mohamedou Ould Slahi became incredibly close while in Guantánamo. She was the only real human contact he had while he was there.

"She was determined she wanted this film to be made and when she realised she was going to be played by Jodie Forster she was totally thrilled.

"Who wouldn't want to be played by Jodie Foster?"

Benedict Cumberbatch plays Lt Col Couch, a military lawyer whose friend, a co-pilot in one of the planes that hit the Twin Towers, died on 9/11.

"He has skin in the game, he has a real blood lust to prosecute Slahi," MacDonald says.

"But slowly he begins to think 'this isn't quite right', and he stands up and says we are not going to go ahead because all of the evidence against this man is tainted because its been extracted in an improper fashion."

Kevin MacDonald is expecting the pandemic to fuel a boom in the creative arts

Three years after work on the film began, it is getting its UK release when the cinemas are closed, but MacDonald, who now lives in London, is delighted it will be part of the Glasgow Film Festival, despite the lockdown.

"I'm a Glasgow boy really," he says. "I grew up in Gartocharn, near Balloch, and all my early film experiences are in Glasgow, that's where I fell in love with film.

"It's always really nice coming to the film festival. Obviously this is not quite the same because you don't get to meet the audience.

"For the filmmaker, what's always so nice about film festivals is you get to talk to the audience and they give you different perspectives on the film, and you meet other filmmakers and learn from them.

"But there's so little culture that can go on at the moment with the conditions that we've got, and for a film festival to happen like this it's a great thing.

"It's also very democratic. Anyone from anywhere can join in this year."

Benedict Cumberbatch has been nominated for a Golden Globe for his portrayal as Lt Col Couch

With two Golden Globe nominations, for Foster and Cumberbatch, already racked up, he is hoping for a good award season to help promote the film.

And he is optimistic about a return to the big screen and its "immersive" experience once the pandemic is over, despite the dominance of online streaming services in the past year.

"People will be desperate to get back out to the cinema after all this," he predicts. "I'm glad that my film is screening at all, but it's not quite the same as being on the big screen.

"My best artistic experiences have always been at the cinema - that's where things have deeply affected me."

"Pent up energy, frustration and political opinions and anger" will fuel the next creative wave, MacDonald believes.

"I think we are going to go through a bit of a rocky road economically and politically. That is always good for the arts, when the arts have got something to talk about, and something to dig into.

"The Thatcher period was great period for music, for film, for theatre in Britain.

"Exploring new worlds, new ways of living, new political possibilities - that's what the arts are so good for, so I'm optimist that the next years are going to be really interesting."

The Mauritanian premieres as part of the Glasgow Film Festival and is available until 28 February. Its full UK release will be on 1 April on Amazon Prime Video.