A Tokyo woman was arrested Tuesday on suspicion of leaving her 3-year-old daughter alone at home for more than a week and letting the child starve to death, police said.

Saki Kakehashi, 24, admitted to the allegations, the police said, adding they believe she had routinely neglected and abused the daughter, Noa.

A friend of Kakehashi's told the police, "She had left home for several days or returned late at night, leaving her daughter unattended," an investigative source said.

Autopsy results showed Noa died from severe dehydration and hunger, they said. The mother is suspected of leaving her alone at home for eight days in early June while visiting her boyfriend in Kagoshima Prefecture, according to an investigative source.

Kakehashi told investigators that she did not expect Noa to die as she thought "it would be alright" to leave the toddler alone in their apartment in Tokyo's Ota Ward, where the two had been living alone since around July 2017 following her divorce from Noa's father.

She made an emergency call upon her return from the trip on June 13, claiming Noa was not breathing. Noa was later pronounced dead at the hospital.

The victim had thymic atrophy, typically observed in abused or neglected children, and her stomach was almost empty, the source said.

Noa suffered a rash on her bottom as her diaper had apparently been unchanged for a long time, and the apartment had large amounts of garbage scattered around it.

During voluntary questioning before her arrest, Kakehashi initially said Noa became ill several days before her death but she had no money to take her to a hospital for treatment.

Noa had not shown up at a daycare center for more than a year, according to the facility.