The parents of an 8-year-old boy in Nagahama, Shiga Prefecture, were arrested on Thursday on suspicion they had left their son chained to a pillar the previous day.

Yasuna Miyajima, 32, and his wife Akane, 27, allegedly left the boy locked up on the first floor of their home for eight hours, starting at around 8 a.m. Wednesday, using a 3-meter chain and two padlocks.

The boy was taken to a hospital but did not have any significant visible injuries, police said.

An officer visited the house after a local child spotted the boy through a window and a neighbor alerted the police. The officer found him chained up in a weakened state and cut him loose using a bolt cutter. A child's potty was found nearby.

The mother and stepfather were not home at the time but have admitted to the charges, according to local police.

On July 16, the elementary school the boy attends told police that he may have been abused, after finding that he had burns and bruises on his body.

School authorities visited the home but took no further action because the boy said he was "all right."