Grijpstra & De Gier is a 1979 Dutch crime film directed by Wim Verstappen.
[1] Although the film was not received to critical acclaim, it managed reasonable box-office success.
The case is originally about a man who seems to have hanged himself but which turns out to be a murder involving the drug trade.
A sequel was made: De Ratelrat, in which Rutger Hauer was replaced by Peter Faber.
The novels were also made into a spin-off television series which ran from 2004 to 2007, with Jack Wouterse as Grijpstra and Roef Ragas as de Gier.