Former Nissan Chairman Carlos Ghosn is likely to appear in a Japanese court to hear the reasons for his detention, possibly within days, after his lawyers deployed a little-used article of the Constitution.
A public hearing could take place within five days, according to public broadcaster NHK, after the executive's attorneys lodged a request with the Tokyo District Court that it cannot legally refuse.
It is the latest in a series of unexpected twists in a case that has gripped Japan and the business world since the once-revered auto tycoon was arrested on his private jet at a Tokyo airport on November 19.
"Mr Ghosn today submitted a request for the disclosure of the reasons for his detention. No date has been set," the court said.
NHK said Ghosn wants to attend the hearing himself if there is one.
Article 34 of Japan's Constitution stipulates that "no person shall be arrested or detained without being at once informed of the charges against him or without the immediate privilege of counsel."