Zhujiang Hospital Associate Professor Yin Fangming was shot dead at 5am on Tuesday near his workplace after a short quarrel with two policemen, who said Yin's front and back licence plates were covered with newspapers.

The bureau said Yin obstructed the officers and grabbed one of their police identity cards. One officer's knee was injured when Yin reversed the car.

An officer then tried to stop Yin driving off with the card.

'The officer was dragged by the car for several metres when he tried to stop it driving away and had to shoot the driver,' the bureau said. Yin was dead on arrival at the hospital.

The bureau said the military licence plates that Yin used had expired and it found two other sets of plates, from Guangdong and Hunan, in his car boot.

It said the city's procuratorate, police and the commission of politics and law had set up a joint investigation into the case.

Authorities have questioned the police involved, a passenger in Yin's car who may be the only non-police witness and doctors and nurses who handled his body on Tuesday morning.

Yin's family and colleagues blamed trigger-happy police and accused officers of covering up.

Hospital staff offered versions of his death that differed from the police statement.

One fellow doctor said Yin had used military licence plates for many years and the colleague did not believe he had covered them with newspaper. The hospital was a military establishment three years ago.

She described Yin as a well-connected person who knew many police, some of them senior district officers, 'so whenever he smashed into somebody's car he could handle everything smoothly by just making a call to his friends in the force'.

'The police are fabricating evidence about the shooting,' she said. 'They controlled all the eyewitnesses and Yin's body so they could smooth over the incident.'

She said she was told police had confiscated Yin's military card and hospital staff card - both of which had expired - after they stopped him. Yin then took the identity card of one of the officers and tried to drive off but police sought to stop him with their vehicle.

'The police shot him twice and the first bullet killed him,' the doctor said.

She said she was told that the State Press and Publication Administration had imposed a nationwide ban on reports of the shooting and online police were patrolling chatrooms to stop discussion.

A source said some doctors protested on Tuesday night in front of public security bureau offices in Haizhu and Yuexiu districts, calling for a fair investigation.

Beijing-based lawyer Xia Lin said police were justified in shooting if their version of the incident was true.

But he noted that so many details were still unclear, including how close the officer was when he fired the shot and why he did not aim at another part of Yin's body.

'Did the police give a warning shot before hitting Yin?' Mr Xia said.

He said he did not agree with some of the doctors' suspicions, saying police usually did not stop vehicles with military licence plates, which meant Yin's plates might have been covered or at least had given cause for suspicion.

'We are hearing so many different versions of the death,' he said. 'I would prefer the procuratorate to lead the case and not the police.'

Armed and dangerous

Some recent mainland shootings involving police

Tuesday

Guangzhou doctor shot dead after being pulled over by public security officers and trying to drive off

Aug 20

Police officer opens fire at 20-year-old man surnamed Tong as he is stealing electricity cables in Zhongshan, Guangdong

Jun 18

Innocent peasant killed when police officer opens fire while chasing robbery suspect in Baotou, Inner Mongolia

Oct 24, '06

Man stealing petrol and spare tyres from vehicles shot dead by police officer in Xian, Shaanxi

Mar 3

Gambler surnamed Han shot dead by public security officer while fleeing in Liuhe county, Jilin. Han's relatives received 300,000 yuan in compensation