The skeletal remains of four babies were found in plastic bags in the Tokyo apartment of a woman who committed suicide last week, police said Monday.

The babies are believed to have died several years ago, considering the condition of the remains found Sunday.

The 51-year-old woman, who began living alone in the second-floor apartment in Ota Ward more than 10 years ago, was found hanging Friday in a park, the police said.

She left a note saying: "I have suffered from money issues. I can't pay rent any more."

The police plan to conduct autopsies on the four babies and investigate the cause of death and the relationship of the children with the woman, including if she gave birth to them.

The woman's younger sister and her husband found four plastic garbage bags in the apartment while organizing the woman's belongings, the police said. When they opened one of the bags, there was a foul smell, and they contacted the police.

The four bodies were wrapped separately in layers of plastic bags, the police said.