A Japanese court rejected Thursday prosecutors' request to extend the detention of former Nissan Motor Co. Chairman Carlos Ghosn, opening up the possibility for his release on bail in the coming days after he was arrested a month ago for alleged financial misconduct.

The prosecutors appealed the Tokyo District Court's decision, but it was also denied. Legal experts believe the court will most likely accept bail requests.

Lawyers for Ghosn and Greg Kelly, a former representative director at Nissan, who have been accused of understating the 64-year-old ousted chairman's pay package over an eight-year period, could seek bail for the two men as early as Friday.

The prosecutors had sought to hold Ghosn and Kelly for 10 more days over additional suspicions that the pair conspired to understate the former chairman's remuneration by 4.27 billion yen ($38.23 million) in securities reports for the three years that ended March this year.

Taking an unusual step, the court rejected a request from the Tokyo prosecutors' special investigation squad, which investigates major political and financial cases.

Ghosn and Kelly were arrested on Nov. 19 on suspicion of understating roughly 5 billion yen of his 10 billion yen remuneration during the five years through March 2015 in Nissan's securities reports. They were indicted on Dec. 10 on a charge of breaching the Financial Instruments and Exchange Act.

The latest request to extend his detention was related to a second warrant for an alleged similar act. The district court also decided against extending Kelly's detention.

The lengthy confinement of the pair has sparked criticism, especially outside Japan, over the possibility that their detention could be legally prolonged indefinitely, and over the absence of lawyers during interrogations.

Some legal experts have accused the prosecutors of "buying time" by relying on the same allegation for separate five-year and three-year periods.

"It is possible to conduct an investigation on eight fiscal years within 20 days," said Motonari Otsuru, Ghosn's lawyer and a former head of the special investigation squad. "Internationally, this is incomprehensible."

"The (two) allegations are the same," said a judge, who spoke on condition of anonymity. "The court may have decided that there was no reason to extend the detention thinking that the prosecutors already had sufficient evidence."

Had the court approved the request, Ghosn would have been detained until Dec. 30, at which point the prosecutors would have had to determine whether to indict him or not, under Japan's Code of Criminal Procedure.

His detention also could have been lengthened had they found new grounds to serve other arrest warrants and should the court approved.

Shin Kukimoto, deputy head at the Tokyo District Public Prosecutors Office, speaking at a press conference, refrained from commenting on the decision.

"We will respond to it properly," he said.

Ghosn and Kelly have admitted to the prosecutors that the former chairman's remuneration was not entirely stated in the reports, but have claimed it was not necessary to do so because the amount of his post-retirement payment had not been settled, according to sources with knowledge of the investigation.

The prosecutors believe the payments were fixed as they have obtained documents on his deferred post-retirement pay, which were signed by Ghosn, a towering figure in the automotive industry who is credited for saving Nissan from near-bankruptcy in the 1990s.

The prosecutors believe the documents are evidence of his intention to falsify securities reports.

One document in English outlined Ghosn's remuneration, including his deferred pay, and was signed by Ghosn and a former head of Nissan's secretarial office, according to the sources.

The contract document listed three different figures, describing his total pay as "determined," the amount actually paid out as "fixed," and the amount not yet paid as "postponed," those sources said.

The prosecutors have also seized an employment agreement document signed by Kelly and Nissan CEO Hiroto Saikawa, who has been questioned by prosecutors on a voluntary basis, according to the sources.

That document states Nissan would pay Ghosn after his retirement for such purposes as consultancy fees.

The documents, managed by Nissan's secretariat office, are believed to have been obtained by the prosecutors as part of a plea-bargain agreement they reached with executives of the automaker, leading to Ghosn and Kelly's arrests.

Ghosn's dismissal from Nissan on Nov. 22 has sparked a power struggle within one of the world's largest automotive groups over the cross-sharing alliance between Nissan, Renault SA and Mitsubishi Motors Corp. which he led.

Even though Nissan has contributed about 50 percent of the French automaker's net income in recent years, Renault owns a 43.4 percent stake in Nissan, which holds a 15 percent stake in its French peer -- but without voting rights -- and 34 percent in Mitsubishi Motors.

Nissan continues to want to review the alliance to make it more equitable, while Renault, whose biggest shareholder is the French government, prefers to maintain its influence within the Japanese automaker and protect its business interests.