Charlie Hunnam will star opposite Lea Seydoux in a ''unique love story''.

The 36-year-old actor and the 'Spectre' actress will appear in director Drake Doremus' upcoming as-yet untitled romance movie, though few other details have been revealed about the project.

A source told The Hollywood Reporter that the movie is a ''unique love story'', but all other details are being kept under wraps for the time being.

Scott Free Productions - the production company owned by Sir Ridley Scott - is producing the movie, whilst the screenplay will be written by Rich Greenberg.

Charlie - who is best known for his role in 'Sons of Anarchy' - will next hit the big screen in Guy Ritchie's 'King Arthur: Legend of the Sword', in which he stars as King Arthur alongside a cameo from former soccer star David Beckham.

On working with the 41-year-old sportsman, Charlie said previously: ''I thought [David] Beckham was a secret but I guess everyone's talking about it now. Unless you just are tricking me and I'm the one that's putting the secret out.

''[David] Beckham was awesome. I mean, I genuinely love that guy. I loved working with him. He was great.''

David's role has not been revealed, but a source previously said: ''There's going to be a version of the scene where Excalibur gets drawn from the stone. This is where Beckham factors in.

''There's a little bit of a sense that Beckham's character, who fancies himself as a big player in this story, gets a little ticked off when this other fellow, this upstart, is the one who can free the sword.''

The movie features Charlie as the titular character, with Eric Bana as his father Uther Pendragon.

Jude Law is lined up as villain Vortigern and Astrid Bergès-Frisbey will portray Arthur's significant other Guinevere.

The story tells of Arthur being unaware of his destiny at first until he stumbles upon the mighty sword Excalibur.

After meeting Guinevere, he then sets about taking his rightful place on the throne, but evil Vortigern stands in his way.