The 31-year-old, born in South Africa, appeared to strike Welsh skipper Alun Wyn Jones in the head with his forearm in the first half of France’s 38-21 home victory.
Referee Karl Dickson and other officials missed the incident but Le Roux now faces a disciplinary hearing on Tuesday.
“Le Roux … was cited for an alleged act of foul play by the independent commissioner appointed by World Rugby,” said a statement from the Six Nations.
“The alleged offense, hitting with the arm (Law 9.12), took place in the 19th minute of the match.
An act of foul play that results in head and / or neck contact can see a player banned for at least six weeks, under World Rugby rules.
France will face Six Nations leaders Ireland on Saturday with Wales hosting Scotland, while England travel to Italy.
France, Ireland second, and England third can all win the rescheduled tournament.
France haven’t won the Six Nations Trophy since 2010 and haven’t finished in the top two since 2011.
(Reporting by Shrivathsa Sridhar in Bengaluru; Editing by Peter Rutherford)