A severed finger was mailed to the French presidency last week, French magazine Valeurs actuelles reported Thursday.
The finger was put in a refrigerator used by police guards for the Elysee Palace-the president's official residence-where it was found late on Sunday night, according to the same source.
The person whose finger was severed was identified and the "necessary process" was launched, a source familiar with the case reportedly said, but no further details were given, including how the individual was known to authorities.
The presidency declined to comment on the situation, the magazine added.
The incident came less than a week before July 14, Bastille Day, France's national holiday, and also fell close to this week's NATO summit in Lithuania, which Macron attended.
Last year Ukrainian embassies in European countries including Spain, Austria, Hungary, Italy, the Netherlands, Poland, and Croatia reportedly received packages containing bloody eyes.
Ukraine and its desire for NATO membership and protection from the nearly 15-month-old Russian-launched war were a major focus of the NATO summit, but it is not known if the war has any connection to the severed eyes or finger.