Prosecutors have confirmed that Nissan's arrested chairman, Carlos Ghosn, is being held in the spartan Tokyo Detention House in Katsushika Ward — its many rules and restrictions making for a stark contrast with his comfortable, globe-trotting lifestyle.

Ghosn is most probably being held in a small 4.8-square-meter room with a toilet at one end, experts familiar with the facility have said. Many of its rooms have traditional straw tatami mats and a futon to sleep on. Other rooms are Western-style with beds, according to a Reuters reporter who has visited the facility. Detainees are allowed to shower on set days, although not every day, said Hideto Ninomiya, a criminal defense lawyer who last visited three months ago.

Rooms lack heaters, for fear of detainees hurting themselves, and have no televisions or radios, he said. Suspects also do not have access to laptops or cell phones.