Produced by Tom Griggs, graphics by Kari-Ruth Pedersen
Carlos Ghosn was one of the most powerful executives in the global car industry, in control of three of the world's biggest carmakers. But on November 19th, his career came to an abrupt halt when he was arrested on suspicion of falsifying his pay and financial statements.
He was ousted as chairman of Nissan Motor, the company he saved from the brink of bankruptcy in 1999. And he later stepped down as chief executive of Renault as well.
Nissan says an internal investigation, triggered by a whistleblower, found serious acts of misconduct. It accuses its former boss of using company expenses for personal use. Tokyo prosecutors have also indicted Mr Ghosn on new charges that revolve around the transfer of his derivatives losses to Nissan and payments that were made to a Saudi businessman after the transfer.
At a court appearance in Tokyo in January, a gaunt looking Mr Ghosn denied all charges, but there is another layer of mystery surrounding the case. Mr Ghosn's plan for a merger of Renault and Nissan was a source of deep tension between him and other Nissan executives. Although the Franco-Japanese alliance is regarded as a huge success that delivered massive cost savings for both companies, it was based on unbalanced structure that gave Renault significantly greater power and control.
When the alliance was formed Nissan was in trouble, and Mr Ghosn and Renault rode to the rescue. But in recent years, the Japanese group has contributed a bigger portion of the alliance's profits. A merger that casts Nissan as the weaker partner would be strongly opposed to Japan. Mr Ghosn's spectacular ousting has led to speculation that it was a coup d'etat to wrestle back control, an accusation that Hiroto Saikawa, Nissan's chief executive, strongly denies.
Both carmakers say they want to maintain the alliance, but trust is at an all-time low. After two decades of working together the companies have combined purchasing functions and use common platforms to build cars, which would be difficult to separate.
The current crisis has made it clear that the existing capital structure is unsustainable. Investors are calling for a deeper integration that will likely take the form of a holding company rather than a takeover. In an era of electric vehicles and self-driving technology, scale is essential to bring down costs. Going solo would be a very dangerous road to take for both companies.