Hugo de Burgh, a journalism professor and expert on China, argued last night that only a "tiny" proportion of people in the world's most populous state were in prison for journalism or blogging.
Speaking at a debate entitled the Great (Fire)Wall of the Internet, Professor de Burgh said it was important not to overstate the curbs on free speech in China, which were often a legacy of confused laws and perpetrated by local officials.
His remarks drew opposition from several of those present at the debate, organised by the London School of Economics and Reporters sans Frontières (RSF).
Julien Pain, head of the internet freedom desk at RSF, said: "There are around 70 journalists in jail in China and more than 50 cyber dissidents also in prison ... How can you say 50 people is not a lot of people?"
Also important was the fear that the imprisonments had instilled in a far greater number of people, including China's estimated 600,000 bloggers, Mr Pain said. "Much of the censorship is self-censorship. People are scared. I would be scared if I faced 10 years in prison for what I wrote."
RSF has recently created an online guide for bloggers and cyber dissidents.
Prof de Burgh, author of China: Friend or Foe, said he supported the work of RSF and groups like Amnesty International in campaigning for freedoms online, but added that it was important China was not stereotyped in the debate.
He said he was sick of listening to "grandstanding" western politicians criticise China while also cracking down on freedoms and being involved in scenarios such as Iraq. He said China was far from perfect but had made incredible strides in recent years and that society was more open than in the past.
But Mr Pain said democratic freedoms were at best static in China and the authorities were beginning to export the technologies they use to control the internet to other regimes around the world. "The technology came originally from US firms and now the Chinese are reselling it ... Every dictator or oppressive regime in the world would like to be able to have this kind of control."
Mr Pain agreed it was important not to focus exclusively on China and said internet freedoms were also being attacked in other places, such as Tunisia. He said a friend was recently in Cuba and had made an internet search with the names of dissidents. A message popped up saying the information could not be accessed because of security issues, and then the software turned itself off.
He called on shareholders of big firms like Google and Yahoo! - which have been accused of cooperating with the Chinese authorities - to demand better regard for human rights when dealing with foreign countries.
Pressure could be brought to bear, he said, citing the refusal of US firms to change their Wi-Fi technology for China, which was suspected of wanting a system it could snoop on. The firms acted out of self-interest because they did not want the cost of adaptations, but China still backed down, Mr Pain said.
Prof de Burgh said there was lots of political debate happening in China and that people at the top of the ruling Communist party were more open-minded about this than was usually acknowledged.
Dr Yuwen Wu, editor of news and current affairs for the Chinese service at the BBC World Service, said bloggers would debate things that the party was already considering, such as judicial reform or fighting corruption.
"They know to be positive and put forward constructive ideas, for example, on how China can better integrate with the international community. But it is dangerous to attack the party or to write about anything ahead of time."
One member of the audience said that the technology to police the web was originally developed to monitor dissident opinion in the US and wondered whether the internet was a "Frankenstein's monster".
