* Ghosn has denied any wrong-doing; says fired unlawfully
* Court hears Ghosn granted himself $8 million in salary, bonus
* Lawyers said he didn't retire 'to go and play golf' (Recasts with details from court hearing)
AMSTERDAM, Feb 10 (Reuters) - Carlos Ghosn, the fugitive former auto executive, used a joint venture between Nissan and Mitsubishi to inflate his pay, effectively clawing back a cut to his declared wages, and to cover a personal tax debt, lawyers for the firms said on Monday.
Ghosn, former chairman of the Renault-Nissan-Mitsubishi alliance, was arrested in Japan in 2018 on financial misconduct charges but fled to Lebanon last December.
He has denied any wrong-doing, including concerning the way he was compensated, and has since launched court cases against the companies, arguing he was fired unlawfully. One of the cases is in the Netherlands, where the Japanese companies made new submissions on Monday.
Ghosn granted himself a salary and bonus worth 7.3 million euros ($8 million) in total without the knowledge of the boards of Nissan and Mitsubishi, the lawyers said.
The companies had previously challenged these payments.
The lawyers alleged in the arguments submitted to the Dutch court that Ghosn had awarded himself that compensation through the Nissan-Mitsubishi joint venture to offset a cut in his publicly-declared earnings, to which he had agreed when stepping down as Nissan CEO in April 2017.
Representatives of Ghosn's legal team said the allegations of unknown or unjust payments were unfounded. They attended the hearing at the Amsterdam District Court, which was linked to Ghosn's unlawful dismissal lawsuit.
"We don't dispute that Mr Ghosn received a good salary", attorney Roeland de Mol said. "But he had the heavy task of getting French and Japanese companies to cooperate. He didn't retire to go play golf after he stepped down as Nissan CEO."
Nissan-Mitsubishi lawyer Eelco Meerdink said there was also evidence that Ghosn made the alliance pay a personal French tax debt of 498,000 euros in 2018, and that he had arranged a "pre-payment" of his 2019 salary in 2018 to avoid a scheduled increase in Dutch income tax rates.
'READY FOR A FIGHT'
The allegations came as Ghosn's legal team challenged his dismissal by Nissan and Mitsubishi during the court hearing in Amsterdam, the first public session on the case after the former executive launched a suit against the companies last July.
Ghosn is seeking 15 million euros in damages from the Japanese carmakers, who, he alleges, violated Dutch labour laws.
Ghosn's lawyers argued for the release of internal documents relating to his dismissal following an Nissan-Mitsubishi inquiry, which the carmakers used to substantiate his dismissal on allegations of financial misconduct.
Ghosn's legal team claims he was unfairly dismissed as chairman of Nissan-Mitsubishi BV, a Dutch-registered entity, because the details of the allegations were not shared with him. His lawyers say the documents will show the companies were aware of his activities.
"Nissan and Mitsubishi publicly shamed Ghosn," de Mol told the court. "Their reports and accusations were never put to Ghosn. There was no due process."
De Mol said he was pushing for "a full debate on the reasons of Ghosn's dismissal. We need the information in his file to be able to do that. Mr. Ghosn is ready for a fight."
Nissan-Mitsubishi lawyer Meerdink dismissed the demands by Ghosn's legal team, saying the reasons for the executive's dismissal were clear, and that his lawyers were "going on a fishing expedition".
The Amsterdam court said it would postpone any decision on documents until Nissan and Mitsubishi file their case on the reasons for Ghosn's dismissal, which is expected on March 26. ($1 = 0.9133 euros) (Reporting by Bart Meijer; Additonal reporting by Laurence Frost; Writing by Anthony Deutsch and Sarah White; Editing by Hugh Lawson and Barbara Lewis)