Christophe Champenois, from Meaux, near Paris, allegedly stripped Bastien naked and shut him in the machine to punish him for a prank at nursery school - throwing a classmate's drawing down a toilet.
He is then said to have run the cold cycle wash for a few minutes at their house, in the village of Germigny-l'Eveque.
The child, whom neighbours described as blond and angelic, died of head injuries on Friday night, French police said.
His mother Charlene, 25, recovered him from the machine, according to Le Parisien newspaper. Read More