Part of what appears to be a car owned by Hikaru Yamato, the last person still missing from the series of earthquakes that hit Kumamoto Prefecture in April, has been found by his parents and friends searching along a river downstream from where he went missing.

According to his father, Takuya Yamato, 58, part of the yellow Toyota Aqua was found Sunday several hundred meters downstream along the river that runs under Aso Ohashi Bridge in the village of Minamiaso.

The 22-year-old Hikaru Yamato went missing on April 16.

Because the vehicle had been flattened by a large rock, they were unable to confirm if anyone was inside.

"I think it's definitely my son's," Takuya Yamato said. He will ask prefectural workers to recover the wreckage as soon as possible.

Hikaru Yamato's parents have been searching the area and distributing fliers.

Rescuers searched for him for weeks after the quake but eventually switched to aerial searches in May out of fear of landslides.

"I want to find Hikaru," Takuya Yamato, who was on verge of tears, told reporters Sunday.

A massive landslide buried part of Minamiaso after a magnitude-7.3 earthquake, the main quake in the disaster, struck early April 16, two days after a high-intensity magnitude-6.4 quake rocked Kumamoto and other parts of Kyushu.