Authorities have discovered a truck cabin that was engulfed by a sinkhole in Japan two weeks ago within a nearby sewer system.

Drone footage indicates that a human body may be inside the cabin, although it remains uncertain if it belongs to the 74-year-old driver who has been missing since the incident.

The sinkhole, which has expanded to a diameter of 40 meters (approximately 131 feet), appeared at an intersection in Yashio city, located near Tokyo, likely due to a rupture in the sewage system.

Search teams face challenges in accessing the 5-meter-wide pipe, primarily due to ongoing water flow and elevated levels of hydrogen sulfide, or sewer gas, officials reported.

To gain access to the truck, a temporary bypass pipe must be installed to divert the water flow, a process that could take up to three months, according to Saitama Governor Motohiro Ono.

While rescuers successfully retrieved the truck’s loading platform from the sinkhole, they were unable to reach the cabin, which was believed to contain the driver.

Shortly after the truck fell into the sinkhole on January 28, the driver managed to communicate with rescuers; however, contact was lost as the vehicle became buried deeper under soil and debris.

On Sunday, authorities shifted their focus from the sinkhole to the adjacent sewer drain, where they uncovered part of a driver’s seat.

Initially, the sinkhole measured just 10 meters wide and 5 meters deep, but it has since grown fourfold after merging with another nearby sinkhole.

As the crater continues to deteriorate, officials have advised local residents to evacuate their homes due to the potential for additional collapses.

Authorities have also requested that the 1.2 million residents of Saitama Prefecture decrease their water consumption, including limiting showers and laundry, to alleviate the water inflow into the underground system.

The combination of escalating water flow and further road subsidence has complicated the search efforts, which have been temporarily halted multiple times for safety reasons.

Sinkholes are becoming more prevalent in Japanese urban areas, largely due to ageing sewage infrastructure.

Officials estimate that repairs to the damaged sewer could take between two to three years.