Tokyo (CNN Business) Carlos Ghosn's wife says she is "fearful and very worried" for the auto executive's health after he developed a fever in a Tokyo jail.

the former chairman of Nissan ( Ghosn,the former chairman of Nissan ( NSANY ), has been unable to speak with his family members directly during the nearly two months he's been detained following his arrest on suspicion of financial misconduct.

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

Japanese prosecutors on Thursday temporarily suspended interrogations of Ghosn, who began feeling ill on Wednesday night, according to the office of his lawyer Motonari Otsuru. Ghosn was also unavailable for a meeting with his Japanese legal team on Thursday.

Ghosn, 64, was told by a prison doctor that he needed rest and was receiving medical attention, Otsuru's office told CNN.