Don't Commit A Sin(1982)

Ferdi Tayfur stars in a powerful dual role as twin brothers whose lives diverge onto drastically different paths. While one brother leads an honest, hardworking life, the other falls victim to a heroin addiction that destroys his marriage and tears his family apart. Determined to pull his sibling back from the brink of total self-destruction, the brother embarks on a painful, high-stakes battle against the ruthless underworld figures exploiting his twin's weakness, risking everything to save him before it is too late.