According to China Trade News staff Lan died of a brain haemorrhage after he was beaten.
"The local authorities haven't given us an official explanation yet and we're urging them to thoroughly investigate and explain," an editor named Wang told Reuters.
Ying Chan, the director of the journalism and media studies centre at the University of Hong Kong, told Al Jazeera that "death or the general victimisation of journalists is not surprising in that particular province ... notorious for its mining disasters".
"There is a well-known collusion between local authorities and business interests," she said.
'Hunting the killers'
A local police official told the Associated Press that Lan's death was being investigated, but said he had not been considered a journalist by the authorities.
|China's soaring demand for energy is keeping |
many unsafe mines open [GALLO/GETTY]
"This is a simple criminal case and we are now hunting the killers," said the official who refused to give his name. He said no suspects had been arrested.
Reports of the case have sparked outrage in Chinese media.
"For a reporter to be beaten to death is undoubtedly a major event in a world that venerates democracy and freedom of information," a comment on the website of the state-controlled Southern Daily said.
"Any country that even slightly values citizens' right to know and freedom of the press would actively and appropriately investigate and deal with this case."
Shanxi provincial officials have reportedly said Lan was not an accredited reporter and suggested that he might have been seeking to extort payoffs in return for not reporting problems at the mine.
That approach was sharply criticised on Wednesday by the Southern Metropolitan Daily, a tabloid based in Guangzhou.
"I don't know whether Lan Chengzhang was reporting or blackmailing, but it is ignorant and disgraceful to absolve thugs of responsibility by citing blackmail," the paper said in a commentary.
Ying told Al Jazeera that the provincial government's approach raised questions.
"I find it curious that claims about 'fake' journalists should start appearing a day after the incident. If you go to the local government website, there is no mention of the tragedy but there is a campaign launched against 'fake' journalists.
"We think it is a spin by local government officials."
Meanwhile, a flood inside an iron mine in northern China's Inner Mongolia region trapped 28 miners on Wednesday, the official Xinhua news agency said.
There was no immediate word on the fate of those trapped in the incident, but rescue efforts were under way, Xinhua said.
According to official figures, China's mines claimed the lives of 4,746 people last year, killed by fires, floods, explosions and other accidents.
Mine owners and managers are often accused of ignoring safety rules in order to speed up production.
Coal mines are particularly prone to accidents with many owners continuing to operate unsafe mines to supply China's huge demand for energy.
Most miners are poor landless farmers with little training and few options for other work.
Labour rights groups say that given that position many miners are easily intimidated by mine owners who frequently employ gangs of armed thugs and have strong ties to local government officials.
The central government has launched periodic crackdowns to close dangerous mines, but critics say many mines often re-open once government inspectors move on.