The lawyers for Nissan's former Chairman Carlos Ghosn, who was sent back to detention while out on bail, have filed a protest with the Japanese Supreme Court.

The appeal was filed Wednesday.

Lawyer Junichiro Hironaka told reporters that Ghosn's fourth and latest arrest is unfair.

Ghosn was arrested in November, released on bail last month but re-arrested last week.

Multiple arrests and long detentions are routine in Japan, but arresting a suspect who cleared bail is unusual.

Ghosn's detention has been extended through Sunday but may be prolonged. He is charged with falsifying financial documents and breach of trust. He says he is innocent.

The latest arrest is over suspicion Nissan money paid to a dealership that was diverted to a company effectively controlled by Ghosn.