An object believed to be a human skull has been found in a vacant house in Tokyo, police said Wednesday.

According to police, the owner of the house in Ogikubo, Suginami Ward, called 110 at around 4:10 p.m. on Tuesday and reported that he had found something that looked like a human skull while cleaning up his house, TV Asahi reported.

Police said the object appeared to be part of a human skull and that remnants of teeth were still attached. It was found on the second floor of the house beneath scattered luggage.

No one has lived in the house for some time. The man told police he lost contact with his sister who used to live there.