In footage posted on Twitter on Thursday, gasps can be heard when the 89-year-old priest, after ordering the infant he is holding to “be quiet”, sharply slaps his cheek. A few seconds later he smacks him again.
The baby's parents, visibly shocked, eventually manage to extricate the child from the priest's grip during the ceremony in Champeaux, about 50 kilometres southeast of Paris.
“This loss of self-control can be attributed to the fatigue of an elderly priest, but that doesn't excuse it,” the diocese of Meaux, which includes the town, said in a statement.
It said the priest would no longer be leading baptisms and weddings nor holding mass until further notice.
“The child was bawling and I needed to turn his head so I could pour the water. I was saying 'be quiet' but he wouldn't calm down,” the priest told France Info radio on Friday.
“It was something between a caress and a little slap,” he said. “I was trying to calm him down, I didn't really know what to do.”