Joaquin Phoenix

Joaquin Phoenix

Joaquin Phoenix is confirmed to star in Spike Jonze's new movie 'Her'.

The 'Walk the Line' actor will portray a lonely writer called Theodore who falls in love with the female voice of his computer's operation system, which is thought to be similar to the iPhone's voice-activated device, Siri.

The film's official plot synopsis, which has appeared on the Annapurna Pictures website, states: "In the not so distant future, Theodore [Joaquin], a lonely writer purchases a newly developed operating system designed to meet the user's every needs.

"To Theodore's surprise, a romantic relationship develops between him and his operating system. This unconventional love story blends science fiction and romance in a sweet tale that explores the nature of love and the ways that technology isolates and connects us all."

Joaquin will be joined in the film by Samantha Morton, Olivia Wilde, Amy Adams and Rooney Mara, who recently replaced Carey Mulligan in the movie.

The project looks set to be released at some point next year, while there has also been speculation the motion picture could arrive on the festival circuit before it hits cinemas.