A 73-year-old man has been arrested in Japan for allegedly confining his son in a cage for over 20 years. Yoshitane Yamasaki was quoted as saying that he locked up his son, now 42, because he had mental problems making him sometimes act violently. The cage was reportedly one metre tall and stood in a prefabricated hut next to his house in the city of Sanda. The son is being taken care by the authorities. According to officials, the son was being properly fed and allowed to bath every other day since his father caged him. Local media, however, reported that he was suffering bent back. The police have reportedly confirmed that Yamasaki had admitted all the allegations.