Ghosn used a joint venture between Nissan and Mitsubishi to grant himself a salary and bonus worth 7.3 million euros ($8 million) without the knowledge of the companies' boards, lawyers for the firms said at an earlier court hearing.

Nissan would seek a refund on the basis that the compensation was not properly authorised, the source said.

Ghosn has repeatedly denied any wrongdoing and one of his attorneys said on Monday that allegations of unknown or unjust payments were unfounded.

(Reporting by Gilles Guillaume, Writing by Sarah White, Editing by Susan Fenton)