A priest and another clergyman were held for questioning Thursday over a packed Easter mass held in Paris in defiance of Covid restrictions, prosecutors said.
Church leaders and the government expressed indignation after images showed the crowded church of Saint-Eugene-Sainte-Cecile with few in the mostly elderly congregation wearing masks.
The newspaper Le Parisien published a video of the service held Saturday showing worshippers packed together, masks not being worn and priests directly placing communion wafers into the parishioner's mouths.
It said the service had lasted four hours.
Paris prosecutors quickly opened an investigation into accusations of knowingly putting the lives of others at risk.
They said Thursday the two men were also being questioned about accusations of failing to wear a mask, and assembling more than six people without respecting distancing rules.
Deputy interior minister Marlene Schiappa this week called the conditions of the mass "unacceptable", while Karine Dalle, spokeswoman for the diocese of Paris, said it was "stunned" by the lack of social distancing at the service, and "such disrespectful behaviour".
Rules stipulate that masks must be worn by all worshippers aged over 11 with two seats left between each person or family group, as well as an empty pew between each row of people.
Separately, the archbishop of Paris on Wednesday said the church had opened an internal procedure against the parish priest at Saint-Eugene-Sainte-Cecile which could lead to sanctions.