Japanese parents arrested for chaining eight-year-old to pillar

Japanese police arrested the parents of an 8-year-old boy for allegedly keeping their child chained to a pillar, according to a local media report.

The couple allegedly locked up their son for eight hours in their house in the western city of Nagahama with a 3-metre chain and two padlocks, the Kyodo News agency reported.

The mother and stepfather have admitted to the charges, Kyoto reported, citing local police.

The child's friends came to the house and spotted him through a window, and alerted police via a neighbour, local media reported.

The police found him chained up in a weakened state with a child's potty nearby, Kyodo said.

The boy was taken to hospital but did not have any significant visible physical injuries, the report said.

The primary school he attended had previously told local police of suspected abuse after finding he had burns and bruises. Authorities visited the home but took no further action because the boy said he was "all right," Kyodo said.

For the first half of 2014, the number of reported child abuse cases grew 43 per cent from a year earlier to 317, the National Police Agency said. But experts estimate the actual number is much larger.