Intikam Benim (1983)

aka's: I Am Revenge/Big Risk/
Vengeance Is Mine

Cüneyt Arkin stars as Eagle Murat, an ex-top cop investigating the death of his identical twin brother. His brother was an undercover narc trying to infiltrate a gang. When Murat learns that his brother is alive, he goes undercover to learn of his brother's whereabouts. Also stars Osman Betin and Emel Tümer. (In Turkish language, with English subtitles).