Thyagi is a 1982 Tamil-language action film directed by C. V. Rajendran and produced by G. Hanumantharao.
The movie stars Sivaji Ganesan as IG Ganesh, who takes the place of his doppelganger Kanwarlal (played by V. S. Raghavan) to infiltrate their gang and gather evidence for justice.
Ganesh witnesses the torture and death of his pregnant wife, the rape and murder of his sister, and is forced to ignore his mother's passing as he carries out his mission.
Despite enduring brutal torture, Ganesh brings the criminals to court, but they are acquitted through extra-judicial means.
The film is a remake of the 1981 Kannada movie "Antha" and was released on September 3, 1982.
The cast also includes Sujatha and Major Sundarrajan in supporting roles.