Police in Izumi, Kagoshima Prefecture, on Sunday arrested a 21-year-old man on suspicion of fatally abusing the 4-year-old daughter of his girlfriend.

According to police, the child, Riara Otsuka, was taken to a hospital in the evening of Aug 28 by her mother's live-in boyfriend, Shun Hiwatashi, who said he had found her unconscious in the bath. She was pronounced dead shortly after arrival.

According to police, an autopsy showed that she had drowned in the bath. However, there were many bruises on her body which had been inflicted over a period of days.

Police say that Riara was beaten by Hiwatashi, a construction worker, who has admitted to physically abusing the girl by punching her in the head with his fist at around 7:30 p.m. on Aug 27.

Local media quoted a neighbor as saying that a girl in the apartment where Riara, her mother and Hiwatashi lived, could often be heard crying loudly some nights.

Meanwhile, police disclosed that in March, when the three were living in Satsumasendai, also in Kagoshima Prefecture, a child welfare center received a report that Riara might have been the victim of child abuse after a video of her being hit was posted online. On March 19, a child welfare official and a police officer visited her home but found no physical evidence that the girl had been hurt. They said Sunday they were not aware that Hiwatashi was living with Riara and her mother.

Riara was also seen wandering outside by herself late at night four times in March and April and taken into protective custody on each occasion. Welfare officials instructed the mother to look after her daughter.

Riara moved to Izumi with her mother and Hiwatashi in July. Child welfare officials in Satsumasendai notified their counterparts in Izumi but no action was taken. Police had requested that Riara be taken into protective custody by local welfare authorities, but they failed to do so because they found no evidence of physical abuse.

Kyodo News reported Monday that Riara's mother had taken her to the emergency department at a hospital in July, saying she vomited after hitting her head while playing. The city had noted the child had several bruises on her body on Aug 5, but did not relay that information to the police. On Aug26, a public health nurse conducted a consultation with the girl but did not find any bruises.

© Japan Today/Kyodo