Rodrigo Santoro will star alongside Will Smith in 'Focus'.

The '300' actor has joined the cast of Warner Bros.' upcoming heist movie which will be directed by Glen Ficarra and John Requa, according to The Hollywood Reporter.

The thriller centres on a master conman (Smith) who falls in love with his young protegee - to be played by Australian actress Margot Robbie - however, he is thrown off his game when his former flame reappears just as he prepares to stage an elaborate heist in Buenos Aires.

Santoro will play the enigmatic billionaire owner of a racing team who is smitten with Robbie's character and hires Smith to give his team a competitive edge.

The actor is best known for playing villain Xerxes in 2007's '300' directed by Zack Snyder and he is set to reprise his role in a sequel film, '300: Rise of an Empire' next year.

The actor recently finished filming 'Jane Got a Gun', a Western film starring Natalie Portman and Joel Edgerton, and will next lend his voice to animated caper, 'Rio 2'.

'Focus' was originally imagined as a starring vehicle for Ryan Gosling and Emma Stone after they worked with the directors on 'Crazy, Stupid, Love'.

Ben Affleck and Kristen Stewart were later linked to the lead roles but pulled out earlier this year.