Tokyo, Dec. 11 -- A Tokyo court ruled Tuesday that Nissan Motor Co.'s former chairman, Carlos Ghosn, and another executive will remain in custody through Dec. 20, more than a month after their arrest. Their detention could continue for months more under the Japanese legal system.

Ghosn's lawyer filed a protest with the court against the prolonged detention, the Tokyo District Court said.

The court decision comes a day after Ghosn, fellow Nissan executive Greg Kelly and Nissan Motor were charged with violating financial laws by underreporting Ghosn's pay by about 5 billion yen ($44 million) in 2011-2015. They were arrested on Nov. 19 and are being held at a Tokyo detention center.

The extension of their detention is to allow time for in...