The man was kidnapped Thursday morning in Paris, the prosecutor’s office said Sunday.

“The victim turned out to be the father of a man who made his fortune in cryptocurrencies, and the incident was accompanied by a ransom demand,” its statement said, without giving their names or other specifics about their identities.

Police investigators located the hostage in a house in the Essonne region south of Paris, from which he was rescued on Saturday night, the prosecutor’s office said.

It said he was treated for injuries but gave no details. French media reported that the alleged hostage-takers cut off one of the man’s fingers.