In Témoin muet, the French adaptation of Agatha Christie's Dumb Witness for the TV series Les Petits Meurtres d'Agatha Christie, Louis Ségur is the parallel character of Charles Arundell from the original story. Louis works in the accounts department of the textile mill owned by his aunt. the wealthy old lady Émilie Longuet, the Emily Arundell parallel. Louis Ségur is portrayed by Olivier Chantreau.
Louis has some of the disreputable characteristics of the original Charles. According to Geneviève Ranson, he has been embezzling money from Émilie's company while working in the accounts department. At the same time, he is a womaniser and he romances both the maid Daisy, Geneviève and even his sister Charlotte. Both Louis and Charlotte blame Émilie for causing the death of their mother, Émilie's sister. Émilie had caught Louis and Charlotte together in the attic once. They pleaded with Émilie not to tell their mother but she did so anyway. Shortly thereafter their mother committed suicide.
Louis' golf club was used to kill Daisy. Laurence makes him swing the club like he would in striking someone. On the basis of this, Laurence dismisses him as a suspect. Although it is not stated explicitly, he swung it in a manner inconsistent with the kind of injuries Daisy sustained.