Inspector Maigret investigates the mysterious murder of a Dutch diamond dealer, found dead in a stolen car. The car belongs to an insurance agent, Michonnet, and has been abandoned in the garage belonging to Carl Andersen.
| Actor | Role |
|---|---|
 Pierre Renoirle commissaire Maigret | le commissaire Maigret |
 Winna WinfriedElse Andersen | Else Andersen |
 Georges KoudriaCarl Andersen | Carl Andersen |
 Georges TérofInspector Lucas | Inspector Lucas |
| AAndré DignimontOscar | Oscar |
 Michel DuranJojo | Jojo |
 Jean GehretÉmile Michonnet | Émile Michonnet |
| ÉÉmile MichonnetMadame Michonnet | Madame Michonnet |
| LLucie VallatMichèle Oscar | Michèle Oscar |
| JJean MitryArsène | Arsène |
| GG.A. MartinNot listed | Not listed |
| BBoulicotNot listed | Not listed |
 Max DalbanNot listed | Not listed |
 Roger GaillardNot listed | Not listed |
| JJean MitryNot listed | Not listed |
 Jane PiersonNot listed | Not listed |
| MManuel RaabyNot listed | Not listed |
| LLucie VallatNot listed | Not listed |