Canada recently revealed that the Iranian embassy (closed in 2012) used to clandestinely pay for teachers and others who worked to recruit Canadians of Iranian ancestry to work for Iran as spies. This was done via special schools (which taught Iranian language and culture) and cultural centers, which were secretly paid for by the Iranian government via an “independent foundation”. These finding came from a Canadian government investigation of Iranian activities before diplomatic relations were cut. The embassy was shut down and diplomatic relations severed largely because it was documented that Iranian diplomats were trying to persuade Canadians with Iranian roots to betray their newly adopted country. Some of these Canadians, who were well educated and talented, were urged to apply for government jobs and rise in the government bureaucracy. The Iranian diplomats eventually discovered that the number of potential recruits was actually very small. By then it was too late because many of those who had already been approached had quietly turned around and reported these recruiting efforts to Canadian police.
It got worse for Iran when Canadian courts ruled that cultural centers and special schools clandestinely operated by the Iranian government could be seized to pay judgments against Iranian supported terror groups like Hezbollah and Hamas that carried out attacks that killed or injured people whose families sued. Iran responded by admitting the secret support for these schools and cultural centers and insisting that this made them embassy property and protected by diplomatic immunity. Iran ignored the original lawsuits but now that property is about to be seized Iran is lawyering up and fighting back. They tried the same tactics in the United States and lost. In Canada the Iranians are making a stronger case that it should have been obvious that all these Iranian cultural organizations must have been paid for by the Iranian government.
Normally Iran prefers to ignore these victim lawsuits because trying to oppose them in court only draws more attention to Iranian activities in support of Islamic terrorism and espionage and subversion in foreign countries. Iran has always denied that it did this sort of thing. But in court cases there is a lot more detail presented and witnesses must testify under oath, so it is more difficult to Iran to try and hide behind denials and claims of diplomatic immunity. Worst of all there’s all that bad publicity. The Canadians were patient, but eventually got tired of Iranian lives and clandestine activities.
The Iranians always felt justified in trying to deceive the Canadians because during the 1979 Iranian revolution, when Iranians violated international law and took captive American diplomats, six of those Americans managed to make it to the Canadian embassy where they were able to eventually get out disguised as Canadians. This infuriated the Iranians when they found out years later. This escape was fictionalized (not all that accurately as far as the Canadian, New Zealand and British contribution was concerned) in a popular 2012 movie (Argo), which won three Oscars and a lot of criticism for playing down the central role of Canadian embassy staff in getting the Americans out in early 1980.