The Tokyo Metropolitan Police Department arrested Kenichi Hosoya, a 43-year-old company executive, and his wife Shiho, 37, of Tokyo’s Taito Ward on Wednesday for allegedly killing their 4-year-old daughter, Yoshiki, by administering psychotropic drugs and antifreeze, investigative sources said.

Police believe that Yoshiki, who was living with her parents together with her 10-year-old brother and 8-year-old sister, had been abused by her parents.

According to the sources, the couple is suspected of giving their daughter the substances on March 12 or March 13 last year.