The welfare ministry has begun a survey of child abuse cases to see if the victims also suffered from sexual violence, with an eye toward tackling the most difficult cases, particularly if they occur within a family, according to ministry officials.

The survey was prompted by the high-profile death of 10-year-old Mia Kurihara in January last year due to physical abuse at her home in Chiba Prefecture. When temporarily in protective custody, she revealed that she had also suffered sexual abuse, the officials said.

In the survey, the ministry is asking all 220 child consultation centers across Japan to report cases in which they initially did not know but later discovered that the abused children had also been exposed to sexual abuse.