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Chairman and CEO of Renault-Nissan-Mitsubishi Carlos Ghosn gestures as he delivers a speech during a visit of French President at the Renault factory, in Maubeuge, northern France, on November 8, 2018. Ludovic MARIN / AFP

Japanese automaker Nissan Motor Co. will fire chairman and CEO Carlos Ghosn after an internal investigation led to his arrest Monday in Toyko for financial misconduct.

Nissan had reportedly been cooperating with investigators after a whistleblower probed into possible improper practices by Ghosn and representative director Greg Kelly that dates back many years. Japanese news service Kyodo News reported that Ghosn and Kelly underreported their income by a combined 5 billion yen ($44 million) from 2011 to 2015.

"The investigation showed that over many years both Ghosn and Kelly have been reporting compensation amounts in the Tokyo Stock Exchange securities report that were less than the actual amount, in order to reduce the disclosed amount of Carlos Ghosn's compensation," Nissan said in a statement.

Nissan will hold a press conference in Tokyo on Monday night.

Ghosn, 64, has been a highly prominent figure in the auto industry and considered a visionary. The Brazilian-born executive spent 18 years at Michelin and then later moved on to Nissan, where he saved the company from collapse and built an alliance with Renault and Mitsubishi. Ghosn has also been an important figure in the emergence of electric cars.

"We are probably the most advanced carmaker in terms of costs of electric cars and we have announced already in 2017 that we are probably the only carmaker who's starting to make money selling electric cars," Ghosn told CNBC in February.

Forbes in 2006 described Ghosn as "the hardest-working man in the brutally competitive global car business."

David Magee, former managing editor of International Business Times and author of "Turnaround: How Carlos Ghosn Rescued Nissan," had access to Ghosn and other Nissan leaders in his 2003 book.

"Carlos Ghosn for many years was one of the most remarkable and powerful global business leaders we have ever seen. But humans are imperfect and ego, greed, and power are always a risk for trouble," said Magee.

"It's still early in this storyline so we don't fully know what happened. We just know that leaders are human, too, and Ghosn was in a position of almost complete power. It's easy to see how one might assume they were owed more money for the work they had done or were owed use of company assets. That would not make it right, however."