TOKYO (BLOOMBERG, REUTERS) - After spending more than a month in a prison room in Tokyo, Carlos Ghosn has developed a fever, prompting the Japanese authorities to stop interrogating the former Nissan Motor Co chairman.

A doctor is attending to the 64-year-old, who is tired from the long detention and interrogations, said his lawyer Motonari Otsuru. Ghosn has been locked up in a small Tokyo jail cell with a toilet and wash basin since his shock arrest Nov 19.

On Wednesday (Jan 9), Ghosn lost an appeal against his ongoing detention, diminishing the prospects of an early release on bail. His current detention term is scheduled to end on Friday. Prosecutors have the right to appeal to a court to extend the detention.

Ghosn's former aide and Nissan director Greg Kelly - arrested the same day as the auto industry icon - was released from jail last month and taken to a hospital afterwards, Kyodo News reported earlier.

Japanese prosecutors plan to indict Ghosn on two more charges of financial misconduct on Friday, a person with knowledge of the issue said, bringing the total number to three.

Ghosn is likely to be formally charged with aggravated breach of trust for temporarily transferring personal investment losses to Nissan in 2008, as well as for understating his compensation for three years through 2018.

The charges add to an earlier charge of under-reporting his income by around half over the five years through March 2015.

At a court appearance this week, Ghosn said all accusations against him were "meritless" and "unsubstantiated".

Nissan also faces an indictment over the latest compensation reporting issue, said the person, who spoke on condition of anonymity due to the sensitivity of the issue.

The Nikkei daily earlier reported that prosecutors planned to charge Ghosn for aggravated breach of trust on Friday. It also reported, citing unidentified investigation sources, that Ghosn had discussed the possibility of extending a three billion yen (S$37.5 million) loan to a business run by a Saudi acquaintance who later provided collateral for a personal investment.

Both the Tokyo Prosecutors Office and Nissan declined to comment on the issues when contacted by Reuters.

Ghosn has said that he has been "unfairly detained" but the Tokyo District Court earlier this week rejected an appeal by his lawyers to end his detention.

It is uncommon for defendants in Japan who deny charges to be granted bail ahead of trial, a practice that has drawn widespread criticism, including from Ghosn's defence team.

A member of Ghosn's Japan-based legal team told Reuters that they would apply for bail after Ghosn's current detention period ends on Friday, but that his release would come next Tuesday at the earliest, should the court accept the application.

Speaking with reporters on Tuesday, Mr Otsuru said he expected prosecutors to take at least six months to prepare for trial.