From loverboy to master manipulator: Bollywood star Saif Ali Khan's transformation into a repellant political operator for an Indian take on Shakespeare's classic "Othello" was no easy task, the film's director says.

Khan reportedly yellowed his teeth and faked a limp to the play the central character, the manipulative Iago -- an unlikely makeover needed to unsettle audiences who see "Omkara," director Vishal Bharadwaj told the Mumbai Mirror newspaper in an interview published on Tuesday.

Khan had "to look like a villain and a political goon" to make the film work, the director said. "I wanted people to get scared after seeing him on screen."

Among Khan's recent hits were sugary romances such as last year's "Salaam Namaste".

Until Omkara, "he had this lover-boy image. So it was a bold step for him to break the image," Bharadwaj said.

The movie is scheduled to be released later this month. It also stars well-known Bollywood actors Ajay Devgan, Kareena Kapoor and Bipasha Basu.