The Brazil-born tycoon is now reportedly set to face a new charge from prosecutors, after he was sacked as Nissan chairman Thursday to top a spectacular fall from grace for the once-revered boss whose fall has stunned the business world.
Prosecutors arrested Ghosn Monday, accusing him and fellow executive Greg Kelly of understating the former chairman's income by around five billion yen ($ 44 million) between June 2011 and June 2015.
But Ghosn is now suspected of under-reporting his income by another three billion yen for the following three fiscal years, the Asahi Shimbun and the Nikkei business daily reported.
Prosecutors are now planning to re-arrest him on charges of understating his income by a total of eight billion yen ($ 71 million) since June 2011, the Asahi said.
Immediate confirmation of the reports was not available.
Under Japanese law, suspects in jail can face additional arrest warrants, which can impose heavier charges.
Ghosn is also suspected of failing to report a profit of four billion yen through stock appreciation rights -- a method for firms to give management a bonus on strong earnings, the Nikkei said.
Separately, the Kyodo news agency has reported that Nissan had paid $ 100,000 a year since 2002 to Ghosn's sister who had no record of doing advisory work for the group.
Deputy chief prosecutor Shin Kukimoto said the Ghosn case is "one of the most serious types of crime" under Japan's Financial Instruments Act, and Ghosn could face a 10-year prison sentence.
His ouster is an astonishing turnaround for a titan of the auto sector who revived the Japanese brand and forged an alliance with France's Renault as well as domestic rival Mitsubishi Motors.
The French and Japanese finance ministers reiterated their "strong support" for the alliance at a meeting in Paris on Thursday.
In a joint statement, Bruno Le Maire and Hiroshige Seko said they both wanted "to maintain this winning cooperation".
Asked about the fate of the alliance, Seko told reporters in Paris: "It is important for people concerned to deal with it after they agree and fully understand.