ES News email The latest headlines in your inbox twice a day Monday - Friday plus breaking news updates Enter your email address Continue Please enter an email address Email address is invalid Fill out this field Email address is invalid You already have an account. Please log in Register with your social account or click here to log in I would like to receive lunchtime headlines Monday - Friday plus breaking news alerts, by email Update newsletter preferences

A man has been arrested in Japan for allegedly keeping his son in a wooden cage for more than 20 years, according to reports.

Yoshitane Yamasaki, 73, claimed he locked his son, now 42, in the one-metre-tall box because he had mental health problems that mean he is sometimes violent, according to officials quoted by public broadcaster NHK.

The cage was allegedly less than two metres wide and stood in a hut by the family home in Sanda, Kyoto.

The son has been taken into the care of authorities.

He was being fed every day, officials said, and allowed to wash every other day since his father locked him up aged about 16.

He is now suffering a bent back, local media report.

He was finally released after a city official paid a visit to the home in January that aroused their suspicions.

The elderly father was arrested in January for 36 hours and it is unclear if further action will be taken.