Tokyo prosecutors have won permission from a district court to extend the detention of Nissan Chairman Carlos Ghosn for a further 10 days, several media reported today. 

Prosecutors had 48 hours after his arrest to either press formal charges, release him or request this 10-day custody extension to continue questioning. 

In a stunning fall from grace for the once-loved tycoon, Ghosn was arrested after arriving in Tokyo on his private jet on Monday. 

His firm Nissan accused him of under-reporting his salary over a period of several years and "numerous significant acts of misconduct." 

Public broadcaster NHK reported that Nissan had paid "huge sums" to provide Ghosn with luxury homes in Rio de Janeiro, Beirut, Paris and Amsterdam "without any legitimate business reason."

Meanwhile, Japan said it is ready to work for the stability of the Nissan-Renault global alliance following the stunning arrest of chairman Carlos Ghosn. 

Nissan has portrayed itself as a victim of Ghosn, one of the global car industry's best-known leaders, who it accused of years of wrongdoing, including personal use of company money and under-reporting earnings. 

It plans to remove him from post tomorrow. 

Japanese prosecutors say he and Representative Director Greg Kelly conspired to understate Ghosn's compensation at Nissan over five years starting in fiscal 2010 as being about half of the actual 10 billion yen. 

The Asahi newspaper quoted unnamed sources as saying that the mis-stating meant Nissan also bore responsibility and that prosecutors were eyeing the possibility of putting together a case against it. 

Ghosn has led the alliance as chairman and chief executive of Nissan's French partner Renault and chairman of the alliance's third partner Mitsubishi Motors. 

The alliance "is a symbol of Franco-Japanese industrial success and we will continue to support it," Japan's top government spokesman said today, calling for a "stable relationship" between the three automakers. 

Japan's Nikkei business daily reported yesterday that Ghosn had received share price-linked compensation of about 4 billion yen over a five-year period to March 2015 but that it went unreported in Nissan's financial reports. 

Renault has tapped its chief operating officer and a senior board member to fill in for Ghosn, but the board refrained from firing him while waiting for details on the allegations - a decision that could buy more time for an accelerated, permanent succession process. 

Shares in Nissan rose 0.8% in Tokyo trade today after falling nearly 6% a day earlier. Mitsubishi Motors was down 0.6% after losing nearly 7% yesterday.