AGENCE FRANCE-PRESSE in Montreal

Iranian activists in Canada are defying strong-arm attempts by the Tehran government to control the internet, and are demanding reforms in their home country during its landmark election campaign.

There are more than 110,000 residents of Iranian origin in Canada, one of the largest exile populations in the world. Many are anxiously awaiting the result of Friday's presidential election runoff in Iran and many use the freedoms they enjoy in Canada to criticise events at home.

"I'm not quite sure why it is the case but Canada seems to be an epicentre for lot of Internet activism," said Ronald Deibert, director of the Citizen Lab at the University of Toronto. "It's probably because Canada has liberal laws when it comes to this issue."

The OpenNet Initiative, a group started by Mr Deibert and colleagues at Cambridge University in Britain and Harvard in the United States, claims Iran is the biggest censor of online content in the world next to China.

The group said in a report released this week that Iran blocks blogs, political websites, those advocating women's rights and any sexual content.

"Iran has put in place one of the world's most extensive and sophisticated internet censorship regimes," said John Palfrey, executive director of the Berkman Centre for Internet and Society at Harvard.

"The regime in Iran treats blogs as newspapers and you have to comply with almost the same rules, or even harsher. So you can't write a blog in Iran unless you use a pseudonym or do not talk about politics," said Hossein Derakhshan, considered to be one of the founding fathers of Farsi-language blogs.

Known online under the pseudonym Hoder, he left Tehran for Toronto in 2000 and two years later began a critical blog about Iran.

Freedom of the press, society, and now the Iranian presidential election are all presented as fodder for the thousands of people who read his daily rants sent via e-mail.

Living in Canada allows him the freedom to express views on many touchy subjects and criticise Iranian politics - something that infuriates officials in Tehran, who often try to censure his blogs and those of other online activists.

In one example of the government's hard line, a 25-year-old internet user in the Iranian holy city of Qom was arrested earlier this month and sentenced to two years in prison for insulting Iran's supreme leader, Ayatollah Ali Khamenei.

"It's definitely making some changes," said Mr Derakhshan, reached by email. "Reformists have been saying that blogs are playing a big role in promoting progressive ideas and breaking the government's monopoly on information."

Most of the Iranian university students in Canada "have blogs and most of them write about politics", said Morteza Abdolalian, himself an Iranian expatriate blogger in Canada.

In his 50s, Mr Abdolalian launched his first blog in September after he edited for many years a newsletter that reports on press censorship in Iran titled Iran Watch Canada.

He remains in regular contact with fellow bloggers in Iran, who report arrests by security officials daily.

"We help each other," said Mr Abdolalian, who translates these clandestine blogs from Farsi to English.