Nissan has sent a no-confidence letter to the board of Nissan Motor Co. Chairman and Chief Executive Officer Carlos Ghosn, accusing him of poor leadership and undermining the main shareholder and rejecting efforts to suspend Ghosn’s power.

While CEO Ghosn, 74, is suspended while a criminal investigation into alleged misconduct is handled by prosecutors, two key witnesses from the auto parts maker are set to appear in the courtroom to question Ghosn directly, and Ghosn’s lawyer is set to question Ross Levinsohn, a former executive at Japanese rival Toyota Motor Corp.

A witness from Nissan for the Yokohama-based carmaker wrote in an open letter seen by Bloomberg News on Thursday that it is the company’s obligation to see that its board follows management’s instructions and as a result of his boss’s actions, he sought to halt or abrogate certain conduct. Nissan’s letter isn’t expected to be heard until Monday when it’s expected to be heard in closed session.

Ghosn is currently unable to speak, and his lawyer is likely to cross-examine officials at the hearing in which they are to be summoned to testify or no longer to be an independent employee. A team of Nissan officials could be called to speak in court.

Nissan is expected to defend its claims against Chief Financial Officer Asaku Okuda and its other senior officers and directors, saying they acted ethically and professionally, with many moving around his office to take notes. It also doesn’t see Ghosn’s treatment of company staff as serious, it said in its letter.

Nissan Chairman Carlos Ghosn Photographer: Kamran Jebreili/Bloomberg

In June, Ghosn quit as chairman of Nissan and threatened his former employer with a non-compete agreement until September 2018. That was after a preliminary investigation confirmed that Ghosn, as CEO, had misused company resources and too influenced financial statements, according to people with knowledge of the situation. He’s also accused of accounting improprieties and breaching his fiduciary duty to Nissan.

A representative for Nissan said in an email late Friday that the company doesn’t want to discuss the matter with other people or the media. The representative declined to comment further.

Kamuzu Suzuki Photographer: James Heredia/Bloomberg

This isn’t the first time the Nissan chairman has faced questions over his leadership.

In 2015, a person familiar with the matter told Bloomberg that Nissan President Marcello Gaspar had offered him $60 million to step down from the top job. In the same month, Chief Strategy Officer Kamuzu Suzuki alleged he didn’t do his job and had abused his position. Gaspar declined to comment at the time.

In February 2017, an email in which Nissan finance chief Satoshi Ozawa and other executives expressed concern over Ghosn’s management plan is said to have been deemed as ill-judged in the bottom half of a “Never ending Failed.”

Earlier this year, Ghosn was temporarily banned from flying and forbidden from any travel outside Japan. He and former Nissan president Hiroto Saikawa were placed under arrest and detained by Tokyo police.

At the time, Ghosn and Nissan executives said they believe criminal charges against him would result in a “conviction that will be harsh” and that the company’s future will be uncertain. He has denied the wrongdoing accusations, and the Nissan chairman may be facing a criminal trial in Japan.

— With assistance by Celia Cheung