CNN  — 

A police investigation has been launched after a chopped finger was sent to the official residence of the French president, according to the Paris prosecutor’s office.

The package delivered to the Elysee palace contained “a piece of a finger, a fingertip it seems,” the prosecutor’s office told CNN on Thursday.

Police opened a case for a “threat of a crime or offense against an elected official” as of Monday, it also said.

The fingertip is believed to belong to the sender, CNN affiliate BFMTV reported.

The Elysee is the official home in Paris of French President Emmanuel Macron, who has held office since 2017.

In the past year, Macron’s government has struggled to ease public anger over a controversial pension reform plan, and then following the police killing of a teenager in the outskirts of Paris.

CNN has reached out to the Elysee for comment.