Ben Foster

Ben Foster

Ben Foster and Chris O'Dowd will star in a biopic about Lance Armstrong.

The 32-year-old actor - who was first linked to play the disgraced cyclist in July - has officially signed on for the lead role in Stephen Frears' biographical film, while O'Dowd will play journalist David Walsh, who was one of the sports writers that uncovered Armstrong's performance-enhancing substance abuse.

'Breaking Bad' actor Jesse Plemons and French star Guillaume Canet have also booked supporting roles in the biopic.

The film will be based on Walsh's book 'Seven Deadly Sins: My Pursuit of Lance Armstrong', which chronicles the journalist's efforts in exposing seven-time Tour de France winner Armstrong for doping in order to win races.

The untitled movie is being scripted by 'Trance' writer John Hodge, while Working Title's Tim Bevan and Eric Fellner will produce alongside Frears' regular collaborator Tracey Seaward.

Armstrong, one of the world's most renowned cyclists, was stripped of all his medals and banned from competitive racing in 2012 following an investigation.

Warner Bros. also has its own biopic about the disgraced star in pre-production, titled 'Red Blooded American'. The film will be directed by Jay Roach and Bradley Cooper is heavily rumoured to play Armstrong.