Hokkaido police on Friday arrested a 22-year-old woman for allegedly leaving the body of a newborn baby in a coin locker at Chitose Station.

The Chitose police arrested Ayano Koseki, who has no fixed address or occupation, on suspicion of abandoning the baby in the locker around May 31. She has admitted to the charges, according to the police.

The police are investigating the relationship between Koseki and the baby.

The locker had been in use for a couple of days when a cleaner who checked inside on Tuesday found the body in a cooler and called the police.

Through an autopsy, the police found that the baby was a boy, but it was not clear whether he died after being born or was stillborn. It is believed that between a week and a month have passed since his death.

Investigators said they believe Koseki is involved in the case based on analysis of security camera footage. Police found her staying alone in a building in Sapporo on Thursday.