Ehud Arye Laniado, 65, was at an unidentified private clinic on the Avenue des Champs-Elysees in the French capital on Saturday when complications during surgery proved fatal.
The experienced diamond expert's heart attack happened when a substance was injected into his penis, Belgian media reported.
Mr Laniado's company Omega Diamonds, which is based in the Belgian city of Antwerp, confirmed his passing.
A statement from the firm said: 'Farewell to a visionary businessman. It is with great sadness that we confirm that our founder Ehud Arye Laniado has passed away.'