Carole Ghosn returned to Japan on Wednesday - days after she left the country to seek help from the French government - and was to be questioned by authorities, a person with knowledge of the matter told Reuters.

"(She) responded in a sincere manner. We believe this will lead to Mr. Ghosn's acquittal," said Ghosn's lawyer Junichiro Hironaka, according to Kyodo.

Carole Ghosn entered the courthouse at around 2:30 p.m. local time (0530 GMT) and left about 2 1/2 hours later, Kyodo reported.

Prosecutors last week arrested the former Nissan chairman for the fourth time on suspicion he tried to enrich himself at a cost of $5 million (4 million pounds) to the automaker. He was previously arrested and charged for financial misconduct and has denied wrongdoing.

Authorities had also wanted to question Carole Ghosn on suspicion that her husband had siphoned funds through a company where she is an executive to purchase two boats, public broadcaster NHK has reported.

Carlos Ghosn, a French, Lebanese and Brazilian citizen, has said he is the victim of a boardroom coup. He is being held in the Tokyo Detention Center, where he spent 108 days after his initial arrest on Nov. 19.

The Nikkei reported that his wife arrived back in Japan at Tokyo's Haneda airport on Wednesday, quoting her as saying she wanted to tell a court that there was "absolutely nothing illegal".

(Reporting by Kiyoshi Takenaka and Chris Gallagher; Writing by Malcolm Foster; Editing by Stephen Coates and Christopher Cushing)

Stocks treated in this article : Renault, Nikkei 225, Nissan Motor Co Ltd