Former Nissan chairman Carlos Ghosn will be detained at least through Jan. 11, the Tokyo District Court said Monday, as the once revered auto industry figure faces allegations that have marked a stunning downfall.

Ghosn, who led Nissan Motor Co. for two decades and helped save the Japanese automaker from near bankruptcy, was arrested Nov. 19 on suspicion of falsifying financial reports. He also faces a breach of trust allegation, for which his detention had been approved previously through Jan. 1.

The Tokyo District Court said in a statement that it had approved prosecutors' request for a 10-day extension.

Ghosn has been charged in the first set of allegations, about under-reporting Ghosn's pay by about 5 billion yen ($44 million) in 2011-2015.

Those close to Ghosn and his family say he is asserting his innocence as the alleged underreported amount of money was never really decided or paid, and Nissan never suffered any monetary losses from the alleged breach of trust.

It is unclear when Ghosn may be released on bail. Tokyo prosecutors consider Ghosn, a Brazilian-born Frenchman of Lebanese ancestry, a flight risk.

In Japan, formal charges can mean a suspect will get detained for months, sometimes until the trial starts, because of fears of tampered evidence.

Another Nissan executive, Greg Kelly, was arrested on suspicion of collaborating with Ghosn on the under-reporting of income and was freed Dec. 25 on 70 million yen ($635,600) bail after more than a month of detention.

Kelly said in a statement released through his lawyers he had suffered while in detention because of his neck ailment and hoped to get medical treatment. He also said he was innocent and hoped to regain his reputation.

"I expect that the trial will start soon. I have not been involved in alleged false entry. I believe my innocence will be revealed in the trial," Kelly said.

Falsifying financial reporting is a serious crime in Japan, with a maximum penalty of 10 years in prison, a 10 million yen ($89,000) fine, or both. But some experts are puzzled that the allegations against Kelly and Ghosn are about underreporting income from Nissan. Nissan is in charge of filing such financial reports, not individual executives.

Past cases of companies and officials getting charged in Japan with falsifying such reports tend to be about misrepresenting company profits or other numbers that relate to the overall operations of the business, not executive compensation.