The Pope’s envoy to France is under investigation for an alleged sexual assault on a male Paris City Hall staffer during an official event last month.

Luigi Ventura, 74, has served as the Papal Nuncio — the pontiff’s diplomatic representative — in Paris since 2009.

He is accused of molesting the man at City Hall on January 17, when the Nuncio attended a New Year’s address to diplomats, religious leaders and civil society figures by the mayor, Anne Hidalgo.

The Paris prosecutor’s office said the investigation was opened after City Hall lodged a complaint six days later. Archbishop Ventura is accused of “inappropriately touching” the man, whose identity has not been disclosed.

He was described as a member of City Hall’s General Delegation for International Relations. “The Nuncio repeatedly let his hands wander,” according to a City Hall source.

A source close to the case said: “This is a complicated matter because Archbishop Ventura is a diplomat and he will want to invoke his right to diplomatic immunity from prosecution.”

Archbishop Ventura declined to comment.