Specialists claim that a local sewer pipe contained a vehicle house that was sucked up by a hole in Japan two weeks ago.
Drone pictures suggest that a human brain is inside the house, but it is questionable if it is that of the vehicle missing 74-year-old motorist.
The sinkhole, which now measures 40m ( 131ft ) in diameter, opened at a road intersection in Yashio city near Tokyo. It is thought to have been brought on by a sewage tear.
Due to constant water flow and higher levels of hydrogen sulfide or drainage oil, research groups are unable to provide the 5m-wide pipe, according to Saitama Governor Motohiro Ono.
To prevent the water from flowing through the vehicle, they will need to install a momentary bypass tube. That process could take three decades, Ono said.
While volunteers were able to remove the vehicle launching platform from the crater, they were unable to achieve the cabin with the driver.
The driver was able to communicate with rescuers shortly after he fell into the sinkhole on 28 January, but contact was lost as the truck was buried deeper in soil and debris.
On Sunday, regulators moved their research from the hole to the nearby sewer tube, where component of a vehicle’s seat was found.
The size of the sinkhole was immediately 10 meters wide and 5 meters deep, but it has since quadrupled as a result of the merger of two adjacent sinkholes.
Authorities have asked near residents to leave their homes as the volcano continues to weaken, feared by more cave-ins.
Additionally, Saitama prefecture’s 1.2 million residents have been asked to reduce their water use, including reducing their showers and cleaning, to decrease the water that flows in the underground pipes.
The research activity, which was repeatedly suspended out of safety concerns, has been hampered by the water flow and additional road collapses.
Sinkholes are extremely common in Asian towns, as many have ageing sewage network infrastructure.
According to officials, the drainage rupture may take two or three years to repair.