Until last Nov. 19, Carlos Ghosn was the stuff of legend — a citizen of Brazil, Lebanon and France who created a global car-making empire uniting Nissan, Mitsubishi and Renault, and who regularly appeared on television and in glossy magazines. Since Nov. 19, Mr. Ghosn has been locked up in a small cell in a Tokyo detention center with a toilet in the corner, endlessly grilled by prosecutors without the right to have his lawyer present. Whatever Mr. Ghosn did or failed to do, this is not how justice is supposed to work.

The charges against Mr. Ghosn (pronounced “Gohn”) are serious. He is accused of underreporting his income by more than $80 million over years and of moving personal trading losses temporarily onto Nissan books. In the immediate wake of his arrest, Mr. Ghosn was dismissed as chairman by Nissan and Mitsubishi, and he was subsequently forced out as chairman and chief executive officer of Renault, in the process losing tens of millions in pay and severance. Nissan is digging up more charges against Mr. Ghosn, and the Securities and Exchange Commission in the United States has begun its own investigation.

The story is a modern take on classic tragedy, the spectacular rise and even more spectacular fall of a larger-than-life business baron. Mr. Ghosn’s arrest has generated reams of Japanese and foreign press reports on his wealth and extravagant life-style, including an elaborate wedding at the Palace of Versailles for which Renault purportedly paid part, and considerable speculation about a plot against him at Nissan, the Japanese automaker he restored to health but kept under the French umbrella of Renault. Though his total compensation might not shock Americans, it was considerably more than Japanese or French corporate chieftains make, which is offered as one reason he might have wanted to conceal the figures.

None of that, however, means that Mr. Ghosn, who insists he is innocent of all the charges against him, should be denied elemental legal protections, or bail. As the weeks have passed and Mr. Ghosn’s requests for bail have been rejected, that is exactly what the Japanese legal system seems to be doing.