Escape from Japan, Carlos Ghosn3 multinational passports owned by ex-CEO Renault-Nissan

The ex-CEO of Renault-Nissan, Carlos Ghosn, made the headlines once again with his leak in Lebanon. But how was he able to leave Japanese territory when his three passports (French, Lebanese and Brazilian) were retained by his japanese lawyers? The businessman would have had a second French passport, but is it legal?