The Man with the Glass Eye(1969)

Original title: Der Mann mit dem Glasauge

A man is found dead in a London hotel. The knife is still firmly stuck in the victim's chest, and Inspector Perkins strangely finds a glass eye in his jacket pocket. Kurt after that a second, mysterious murder happens: A city-famous dancer of the Las Vegas Girls, who perform at the London Odeon Theater, is poisoned. Is there a connection between the pretty dancer and the hotel guest? Inspector Perkins and his colleagues are pressed for time. The "man with the glass eye" strikes deadly again and again. A first clue leads Scotland Yard to a billiard club, where one has to show a glass eye as an admission ticket.