Two executives of a nationwide chain of day-care centers were transferred by police Monday to prosecutors on suspicion of negligence resulting in the March death of a baby placed in their care in a Tokyo facility.

The two executives are Masamitsu Maekawa, 53, president of Chibikko-En, and Kozue Maedomari, 37, a director of the Toyama-based company. The chain operates 63 day-care centers nationwide.

Police said they also transferred to prosecutors the 29-year-old head of the Chibikko-En Ikebukuro Nishi facility in Toshima Ward where the baby died.

Also Monday, the Tokyo Metropolitan Government dispatched personnel to investigate the company's 14 facilities within the capital.

The probe is aimed at determining how personnel at the day-care centers are handling the incident and to ensure operations are running smoothly, Tokyo officials said.

According to police, 4-month-old Ryosuke Hojo was found unconscious March 15 after he and an 8-month-old baby were placed in the same cot for a nap at the Chibikko-En Ikebukuro Nishi facility. Hojo died the following morning.

The other baby apparently rolled over onto Ryosuke's face while they were sleeping, causing him to suffocate, police said.