Police in Japan have arrested a 27-year-old man after he admitted to killing an unidentified person and dismembering the body.

Japanese media reported parts of as many as nine bodies were found in the apartment of Takahiro Shiraishi in Zama City, Kanagawa Prefecture, southwest of Tokyo.

Shiraishi has been arrested on the charge of abandoning a corpse, police told CNN, and investigation is still ongoing. The names, ages and genders of the alleged victims have not been revealed.

"I killed (a person) and dismembered the body and put them into a cooler box with cat litter in order to hide the evidence," Shiraishi said, according to police.

A police officer would not comment on the eight other bodies reportedly found in Shiraishi's apartment.

According to Japanese public broadcaster NHK, police searched Shiraishi's home as part of an investigation into the disappearance of a 23-year-old woman from Hachioji City, in the Tokyo suburbs.

Investigators told NHK the woman was reported missing last Tuesday after she posted a message online saying she was looking for someone to join her in committing suicide. Surveillance footage showed her walking with the suspect near the man's apartment.

When they searched Shiraishi's apartment, police found the dismembered body parts of nine people, hidden around the apartment, NHK reported.

Citing police sources, TV Asahi reported three cooler boxes and five containers were found in Shiraishi's room containing human heads and bones with the flesh scraped off.