The driver of the truck responsible for the death of hero bus driver Wu Bin could face criminal charges, a legal expert at the Ministry of Transport said.

Wu Bin, 42, was killed on a highway in Wuxi on June 1 when part of a broken brake hub smashed through his windshield and hit him in the stomach.

Police said on Thursday they had found the truck that caused the tragedy. However, no information has been released about the whereabouts of its driver.

Zhang Zhuting, a law professor at the ministry's transport management institute, said whoever was behind the wheel should take the blame.

"Regulations state that all drivers are obliged to make sure their vehicles are safe before hitting the road," he said. "In this case, the driver has failed to maintain his truck properly and the brake drum has led to the death of the bus driver."

He said judicial authorities will make the final decision after further investigation.

Traffic police in Wuxi, Jiangsu province, said in a statement that the truck - an old, red Dongfeng model - was found early on Wednesday in Yichun, Jiangxi province, with the help of local police.

Investigators discovered the vehicle, one of more than 3,000 possibly linked to the accident, had been fitted with a new brake drum on June 1.

Wu was fatally wounded when a 3.5-kg fragment of metal came hurtling at his bus from the oncoming side of the road. Despite his injuries, he managed to safely stop the vehicle and ensure his 24 passengers escaped unharmed.

He died in a hospital on June 1 and was hailed as a national hero. His family was granted a number of awards.

Zhang urged authorities to do more to ensure the quality of tests for trucks on the nation's roads.

"Society has become more concerned about the safety of cars, and cars are always recalled in a timely fashion whenever there are quality flaws," he said. "However, trucks are seldom recalled."

Jin Songtao, director of technology and quality at Chongqing Vehicle Test and Research Institute, said that the quality test of newly made vehicles does not include a check on brake hubs.

"Brake hubs of new trucks are always of good quality, but they should be maintained regularly after the trucks have been used for years," he said.

Wang Qiang, a 33-year-old truck driver from Rizhao in East China's Shandong province, said that the brake hubs of trucks should be replaced every two or three years based on the frequency of the trucks' usage.

"Overloaded trucks are more likely to have problems with the brake hubs," he said. "It takes a longer time for an overloaded truck to brake, during which time there is more heat created, posing a threat to brake hubs."

Traffic police don't test brake hubs in the annual quality check of trucks, and most drivers neglect the maintenance of brake hubs, he said.

The truck driver in questions is unlikely to have found out in time that the 3.5-kg piece of brake hub had broken off from his truck, Wang said.

Xu Wei contributed to this story.

Contact the writers at wangzhenghua@chinadaily.com.cn and anbaijie@chinadaily.com.cn