Interesting! Just been perusing
www.cannon.org.uk – a UK website that's devoted to the now defunct company owned by Israeli cousins Menahem Golan and Yoram Globus. There's a section on the site called 'Cannon Could Have been' linked to a collection of projects that the company was developing but for whatever reason, never materialised. One of them is from a script by Paul Schrader and it's called INVESTIGATION. The film was intended to Al Pacino and Andrei Konchalovsky of TANGO AND CASH fame was slated to direct.
Review of Paul Schrader's INVESTIGATION scriptIt's safe to say that the writer of the review hasn't seen or even knew about the Petri film.
Obviously, a remake of this film would have been completely unnecessary but with Schrader writing and a younger Pacino acting, I would have certainly watched it. Also, had this been made, it's a safe bet that there would be a legitimate, English-friendly release of Petri's film on DVD now.