Ousted Nissan Motor Co. Chairman Carlos Ghosn's health has improved after he developed a fever earlier this week while in detention, one of his lawyers said Friday.

Ghosn fell ill Wednesday evening, and his family in Paris issued a statement the following day expressing their concern and asking Japanese authorities to provide information on his health.

"I recently learned that my husband is suffering from a high fever at the detention center in Tokyo, but my information is limited to news reports as no one in his family has been allowed to contact him since November 19," the statement by Ghosn's wife Carole said.

"I am pleading with the Japanese authorities to provide us with any information at all about my husband's health. We are fearful and very worried his recovery will be complicated while he continues to endure such harsh conditions and unfair treatment," it said.

Ghosn's lawyers are now able to meet him. They were unable to do so on Thursday as a doctor at the Tokyo Detention House said he needed some rest.

The prolonged detention of the 64-year-old, who remains a Nissan board member and chairman of Renault SA, has put under international scrutiny Japanese criminal procedures that effectively enable investigators to keep a suspect in custody indefinitely by serving fresh arrest warrants.

On Tuesday, Ghosn made his first public appearance since his arrest about seven weeks ago, seeking an explanation in an open court hearing on his prolonged detention and declaring his innocence regarding the allegations against him.

Ghosn was arrested on Nov. 19 along with his close aide Greg Kelly for allegedly understating the former chairman's remuneration in Nissan's securities reports submitted to Japanese regulators, and the two were indicted on Dec. 10.

Ghosn's detention has been extended due to a fresh allegation that he transferred personal investment losses to Nissan during the 2008 global financial crisis. Prosecutors indicted him on the charge on Friday.

Kelly, in contrast, was released on bail on Dec. 25 and his lawyer said Friday he has since undergone surgery for spinal stenosis at a hospital in Ibaraki Prefecture and moved to a residence approved by the court. Before his arrest, he had been scheduled to undergo surgery on Dec. 7 in Tennessee, according to his family.

Ghosn suffers high fever, interrogation suspended