Mitsubishi joined Nissan in ousting Carlos Ghosn as its chair Monday (November 26).

It's a spectacular downfall for Ghosn - who was once one of the most well-known figures in the industry.

He was arrested last week and is being investigated for allegedly understating his income and using company money for personal use.

It's fueled a power struggle within a corporate alliance that as a group rank as one of the world's biggest automakers.

It includes Japan's Nissan and Mitsubishi, and France's Renault - which is yet to fire Ghosn from his position as chair and CEO.

The head of Nissan reportedly told employees on Monday that its relationship with Renault was not equal - and needed to be reviewed.

The top alliance execs will be meeting in Amsterdam this week, in a bid to shield their joint operations from the fallout.

The automakers have stressed that it's business as usual - though Nissan has already postponed a product launch, it says that was to ensure the event receives coverage it merits.

Ghosn has denied the allegations against him, according to Japanese public broadcaster NHK on Sunday (November 25).