Boronad, 30, is registered with AS Cannes and his contract expires at the end of the month.
But a statement from Elland Road says: "Leeds United can confirm that, despite reports in France and claims suggesting otherwise, the club has not signed French player Guillaume Boronad. The club has not had any contact with the player, is unaware of who the player is and we can categorically confirm that he has not even been offered, or signed, a contract with Leeds United."