According to Mehta, the 46-year-old readily agreed to play the character of a lawyer and mentor to actor Rajkumar Yadav in the film.
"Tigmanshu is a colleague whose work I have admired ever since he was directing for television. Asking him to act in 'Shahid' was a spontaneous decision taken after my casting director Mukesh Chhabra told me that how brilliant he was in 'Gangs of Wasseypur'.
"He is a brilliant though reluctant actor. 'Shahid' is a special film and friends like Tishu have made my film that much more special by going all out to support me," Mehta said.
"Shahid" is based on the life of slain human rights activist and lawyer Shahid Azmi, who was killed in 2010 by unidentified assailants in his office. After travelling to festivals like Mumbai, Toronto and Dubai, it is being released by Disney-UTV on October 18 in India.