Ghosn and co-accused Greg Kelly, a former Nissan Motor Co Ltd representative director, are likely to be charged the same day, the Nikkei reported on Friday.

However, their release is unlikely as prosecutors are expected to re-arrest them for mis-reporting compensation for three additional years, the financial newspaper said, beginning another detention period of up to 22 days.

HOW CAN GHOSN BE RE-ARRESTED?

Repeatedly arresting individuals on slightly different allegations linked to the same case is a relatively common practice in Japan. It allows prosecutors to hold suspects while they pursue investigations and also means they can continue interrogations without the presence of a lawyer.

Domestic media have reported that Ghosn and Kelly denied wrongdoing, though their lawyers have not issued statements.

CAN GHOSN BE FREED ON BAIL?

If Ghosn is re-arrested, he will remain in detention for up to another 22 days. After that, if he is not re-arrested, Ghosn may be considered a flight risk and denied bail, legal experts said.

Prosecutors are reluctant to grant bail to those who insist on their innocence, said Nobuo Gohara, a former prosecutor who was previously a member of the Tokyo prosecutors' office Special Investigations Unit, which is leading the Ghosn investigation.

This has led to criticism of a "hostage-based justice system," whereby individuals are held until confessing to crimes, Gohara said.

DOES NISSAN BEAR ANY RESPONSIBILITY?

Legal experts have pointed out that preparing accurate financial documents is the responsibility of the company, and so have questioned why only the two executives had been accused.

However, on Friday, the Nikkei said prosecutors are likely to hold Nissan accountable for publishing the statements which allegedly misrepresented Ghosn's remuneration.

Nissan and the Tokyo District Public Prosecutors Office declined to comment when contacted by Reuters.

HOW ARE SUSPECTS TREATED IN JAPAN?

Individuals arrested in Japan are held mostly incommunicado in small, sparse cells with an exposed toilet for as many as 23 days, depending on whether it was the police or prosecutors which arrested them.

Lawyers can visit clients in detention but cannot be present during interrogation sessions, which can last eight hours a day, for several days.

"Suspects become anxious and lose confidence in what they're saying," said Osaka-based lawyer Masashi Akita, who has won only a fraction of his criminal cases over 30 years' practice. "What's especially hard is that suspects say prosecutors won't listen no matter how many times they repeat themselves."

The Japan Federation of Bar Associations, the United Nations and human rights groups have criticised such practices. Critics have also questioned Japan's 99.9 percent conviction rate.

"Each country has its own culture and systems," said Shin Kukimoto, deputy public prosecutor at a news conference last week. "I'm not sure it's right to criticise other systems simply because they are different."

It is not as if the system immune to reform, however. Starting next year, interrogations must be recorded in cases initiated by the Special Investigations Unit. Prosecutors said they are recording the questioning of Ghosn.

COULD THE WHISTLEBLOWER ACCEPT A PLEA BARGAIN?

Chief Executive Hiroto Saikawa said Ghosn's alleged misconduct was exposed by a whistleblower, whose identity has not been disclosed. However, it is not known whether the whistleblower was simply aware of wrongdoing or party to it.

If the latter, prosecutors could ask the whistleblower to testify against Ghosn in return for leniency. Such plea bargains were only introduced to Japan's legal system in June and have so far been used just once.

(Reporting Malcolm Foster; Additional reporting by Kiyoshi Takenaka; Editing by Christopher Cushing)

By Malcolm Foster