Ghosn has not commented publicly on the case since his arrest last Monday.
But he has told Japanese prosecutors that he did not intentionally understate his income on financial reports, public broadcaster NHK reported.
He and fellow executive Greg Kelly are suspected of understating his income as chairman of the Nissan board by about five billion yen (39 million euros) between June 2011 and June 2015.
Kelly also denies the allegations.
On Friday Japanese newspapers said that prosecutors have also accused Ghosn of doing the same for the three following financial years, bringing the total to eight billion yen (62 million euros).
Ghosn remains Renault boss
The governing body put in charge of Renault since Ghosn's arrest has ordered an internal audit on pay and potential abuse of corporate assets, Le Maire told BFMTV on Sunday.
He dismissed rumours that Ghosn was the victim of Japanese efforts to prevent the complete merger of the three carmakers, saying "I don't believe in conspiracy theories."
Top executives of the three companies plan to hold a meeting this week, their first gathering since his arrest, local media said.
The meeting will be held in the Netherlands with a video conference available for executives who cannot attend, the Yomiuri Shimbun said.