Nissan Chairman Carlos Ghosn, one of the auto industry's most high-profile executives, has been arrested by prosecutors in Japan after an internal investigation revealed "significant acts of misconduct" over many years by him and another top executive.

Nissan Chairman Carlos Ghosn, one of the auto industry’s most high-profile executives, has been arrested by prosecutors in Japan after an internal investigation revealed “significant acts of misconduct” over many years by him and another top executive.

The stunning announcement ripped through a powerful global alliance of automakers, slamming the stocks of Nissan and Renault, where Ghosn also serves as chairman.

Together with Japan’s Mitsubishi Motors, Nissan and Renault make up the biggest global carmaking alliance, which manufactures one of every nine cars sold around the world.

Nissan said in a statement that it had been investigating Ghosn, a 40-year veteran of the auto industry, and another board member for months following a whistleblower report.

“These two gentlemen were arrested this evening, that is what I understand,” Nissan CEO Hiroto Saikawa said at a press conference in Tokyo late on Monday.

The company said its investigation found that Ghosn, 64, and the other board member, Greg Kelly, had been under-reporting Ghosn’s compensation. “Numerous other significant acts of misconduct have been uncovered, such as personal use of company assets,” it added.

As a result, CEO Saikawa will propose to Nissan’s board of directors to “promptly remove Ghosn from his positions as chairman and representative director,” at a meeting on Thursday, the company said. He will also try to have Kelly removed from the board.

Renault and Nissan shares plunge

Shares in Renault, where Ghosn is chairman and CEO, plunged as much as 13 percent in Paris. Renault didn’t immediately respond to a request for comment.

French President Emmanuel Macron said the government was watching closely.

“The state, as a [Renault] shareholder, will be extremely vigilant regarding the stability of the alliance and the group,” Macron said during a visit to Belgium.

Nissan’s announcement came after the close of trading in its stock in Tokyo. But its shares plummeted 10 percent on the Frankfurt stock exchange.

“Nissan deeply apologizes for causing great concern to our shareholders and stakeholders,” the company’s statement said. “We will continue our work to identify our governance and compliance issues, and to take appropriate measures.”

Global shockwaves

Ghosn is also chairman of Mitsubishi Motors. CNN wasn’t immediately able to reach Mitsubishi for comment outside of regular business hours.

Under Ghosn, the three carmakers formed an alliance that rivals Volkswagen and Toyota in terms of vehicle sales. The alliance sold 10.6 million vehicles last year. Together, Renault, Nissan and Mitsubishi employ more than 470,000 people in nearly 200 countries, according to the alliance’s website.

Nissan’s revelations came after Japan’s Asahi Shimbun newspaper and broadcaster NHK reported that prosecutors were questioning Ghosn on suspicion of under-reporting his salary and may arrest him.

The prosecutors’ office didn’t respond to a request for comment outside regular office hours. CNN wasn’t immediately able to reach Ghosn, Kelly or their representatives for comment.

Nissan said it paid Ghosn a salary of 1.1 billion yen ($9.7 million) in the year ended March 2017, his last as CEO. Nissan doesn’t break out individual board members’ compensation in its annual report.

A company spokesman didn’t immediately respond to a request for more information about Ghosn’s compensation.

A career spanning continents

Born in Brazil, Ghosn started his career at French tire maker Michelin in 1978, working his way up to running the company’s North American operations.

He moved to Renault in 1996. After the French carmaker established its alliance with Nissan in 1999, he became the Japanese firm’s chief operating officer, helping steer it out of financial crisis.

Ghosn was promoted to CEO of Nissan in 2001, and then made the unusual move of taking on the role of Renault CEO in 2005. That made him the first executive to run two Fortune Global 500 companies at the same time.

After Nissan took a 34 percent stake in Mitsubishi Motors in 2016, Ghosn handed off the Nissan CEO role to Saikawa.

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