The Metropolitan Police Department rearrested Kenichi Hosoya, 43, and his wife Shiho Hosoya, 37, both company executives, on Wednesday on suspicion of murdering his sister in 2018, following their initial arrests last month for allegedly killing their 4-year-old daughter.
Kenichi Hosoya said he couldn't comment for now and Shiho Hosoya has remained silent, according to police.
The couple have been under detention since last month on suspicion of administering psychotropic drugs and antifreeze to their daughter Yoshiki, resulting in her death in March 2023.