A 35-year-old man from Sakai, Osaka Prefecture, and his 32-year-old wife were arrested on suspicion of unlawfully receiving child care allowances for a boy who was last seen about three years ago and would be 4 now, investigators said Tuesday.

According to the investigators, Suguru Kajimoto, a reinforcement bar worker, and his wife, Chiho, were arrested on suspicion of fraud for allegedly receiving roughly ¥360,000 between April last year and February. They have reportedly denied committing fraud but are refusing to reveal the fate of their son, Tatsuki.

Kajimoto initially told the police that his son suffered a fatal fall from a stairway and that he dumped the boy's corpse into the sea, but then he later refused to disclose his son's whereabouts. His wife said Kajimoto took their son away around last Christmas and she doesn't know where he is. The police are investigating the disappearance.