Prosecutors said on Thursday that they had arrested Mr. Ghosn on suspicion that he used a Nissan subsidiary to send payments to a company business partner, who then sent money to a third company Mr. Ghosn controlled. Prosecutors didn’t disclose the name of the business partner. Nissan’s internal investigation has found that Mr. Ghosn authorized over $30 million in payments over seven years to a business partner in Oman, according to a person familiar with the report, who spoke on the condition of anonymity because the findings are not public.

Mr. Ghosn’s legal team has defended the payments as legitimate disbursements. Nobuo Gohara, a Japanese prosecutor turned defense lawyer, said the unusually forceful approach to Mr. Ghosn on Thursday could signal doubt among the authorities.

“The prosecutors have a real sense they’re in danger,” said Mr. Gohara, who is not a member of Mr. Ghosn’s defense team. “If things continue this way, there’s a possibility that they’ll lose at court. So, they’re doing things without regard to how they look.”

Mrs. Ghosn, 52, has largely been on the periphery of the allegations against her husband. Her name previously appeared in relation to a wedding party at Versailles that was at the center of an internal investigation by Renault. The company has said it turned over information to French prosecutors regarding the celebration and whether Mr. Ghosn had inappropriately spent company funds on it. He has denied the allegations, but offered to reimburse the money.

In her interview, Mrs. Ghosn described a wide and thorough search of their Tokyo home. “They checked every paper,” she said.

“I have a business card from my hairdresser,” she added. “They took it. My Bloomingdale’s card. They took pictures of all my credit cards. I was treated like a criminal.”

Mrs. Ghosn said the authorities had demanded that she and her husband turn off a camera that was installed in their home as a condition of Mr. Ghosn’s bail. Eventually, the men put a piece of paper over the lens so it could not record the search, she said.