Les Héritiers (1960)

Rival brother and sister Gaëtan and Chantal, the last heirs of the late billionaire financier Omar Porassis, use every trick in the book to try and claim his fabulous inheritance when two of Omar's natural sons, Roger and Marc, are found. The brother and sister try to manipulate Marc and Roger into stealing their inheritance. After discovering the deception, the two half-brothers join forces to escape the many traps set by Gaëtan and Chantal, who try to eliminate them by any means necessary.