The Shanghai government is looking into the latest complaint of traffic authorities entrapping a taxi driver while investigating illegal cab operations.

The driver, Sun Zhongjie, 19, was so upset over the accusation that he cut off a piece of his little finger on his left hand to prove his innocence. He was sent to hospital immediately for surgery.

"The doctor told me my finger may never recover its normal function," he said.

In the evening of Oct 14, Sun, driving a mini van, was sent by his employer, Shanghai Pangyuan Construction Machinery Engineering Company, to pick up someone at Hangtou Town in Pudong district. He arrived Shanghai only two days ealier from his hometown in Henan province.

"It was late and there were few cars on the street," Sun told China Daily.

"Then I saw a man standing in the middle of the road and waving to me. I stopped the car and he opened the door and got in without asking me. Then he told me he was sick and cold, begging for a lift.

"I started the car. And in three minutes, at an intersection, a van slid from the right side and stopped in front of me."

Sun stopped the car and the hitchhiker threw a 10-yuan-note to Sun and jumped out. He disappeared when several people walked up to him and claimed they were from traffic enforcement.

"I thought they were robbers. I wanted to call police and they grabbed my phone. They told me that I had engaged in an illegal cab operation, which is not true," he said.

The vehicle was confiscated and Sun was given a receipt from the Shanghai Traffic Law Enforcement Team for Pudong New Area, asking him to go to their office later to pay the fine and claim the van. According to traffic rules, Sun will have to pay a 10,000 yuan fine if the charge is proven true.

"I went back to my company and I was blamed for the incident. My brother said it was obviously entrapment and I should not have let the man in," he said.

"I felt so angry and insulted and I cut off my finger."

But the authorities have denied it was entrapment. Yan Liangming, deputy general commander of the traffic team, said during a TV interview: "The hitchhiker was not our man."

He also said the team had evidence to back up their actions.

Zhang Liwei, an official with Shanghai Traffic Law Enforcement General Team, told Shanghai Evening News on Friday that none of the 15 district teams hired private agents to entrap drivers. But people who help catch illegal cabbies can receive bounties of 200 to 300 yuan.

On Sunday, the Shanghai municipal government responded in a statement that it will look into the situation.

"Enforcement of traffic rules must conform to law. Illegal enforcement will be punished once proved," the statement says.

However, such incidents have been revealed rarely.

The Pudong traffic authority declined comment. About one week ago, Shanghai's Minhang district court accepted a lawsuit by a driver against the district's Traffic Law Enforcement Team, which fined him 10,000 yuan for operating an unlicensed cab. The driver, Zhang Jun, said he was entrapped.