Police officers have found severed heads and human body parts inside a flat, a finding which has sparked serious tension in the area.

According to a Daily Star UK report, some severed heads and body parts belonging to at least nine people have been found in a flat.

Police made the grisly discovery at an apartment in Zama, a city just outside Tokyo, Japan.

At least two heads and other body parts belonging to at least nine people were found stored in picnic cooler boxes after officers went to investigate a "nasty smell" coming from the flat.

Cops were also probing the disappearance of a 23-year-old woman, who went missing earlier this month.

She was reportedly last seen walking with a man near the apartment on CCTV footage.

A DNA test will be carried out in due course in a bid to identify the remains.

Their causes of death have not been revealed.

A neighbour revealed a vile odour had been coming from the apartment for months before the gruesome find.

She said: “There's been a nasty smell coming from that apartment. I first noticed it back in August.”

A Japanese man has now been arrested and is being held by police on charges of discarding a dead body.