Japanese police say the mitochondrial DNA type of a human bone fragment found in a mountain area in Yamanashi Prefecture matches that of the mother of a girl who went missing three years ago.

The police say it is "not contradictory" to say that the bone belonged to a person with blood ties to the mother.

In September 2019, Ogura Misaki, then a first-grader, went missing from a campsite in Doshi Village in the prefecture. Massive search efforts failed to find her.

On April 23 this year, part of a human skull was found in a valley about 600 meters from the campsite.

Police could not collect enough DNA to identify the person from the remains.

So they studied the mitochondrial DNA in the bone cells to examine blood relations. Mitochondrial DNA is maternally inherited.

As they continued searching the valley and surrounding areas, police found a pair of shoes and a sock in late April. They also discovered a shoulder blade and a long-sleeved shirt on May 4, and two objects that looked like bone fragments on Wednesday.

Police say the shoes and shirt closely resemble those the girl was wearing the day she disappeared.

They say they will continue examining the shoulder blade and the apparent bone fragments.