Zahra Kazemi's death in July 2003 strained Canada-Iran ties
A court in Canada has begun hearing a lawsuit filed by the son of slain Canadian-Iranian photojournalist Zahra Kazemi against the Iranian government.
Zahra Kazemi died in 2003 after receiving head injuries during more than three days of interrogation.
Her son, Stephan Hachemi, is trying to sue Iran for C$17m (£9.7m) over her arrest, torture and death.
Iran argues it cannot be sued because of an immunity law that shields foreign governments on Canadian soil.
Zahra Kazemi, who held both Canadian and Iranian nationality, was arrested in 2003 while photographing the relatives of detainees outside Tehran's Evin prison.
She was never formally charged but died in detention less than a month after her arrest.
Official Iranian reports initially said she had died form a stroke but a subsequent inquiry found she had been killed by a "physical attack".
An intelligence agent accused of beating her to death was acquitted in 2004.
Her body was buried soon after her death and no post-mortem examination was ever carried out.
As well as seeking $17m, Mr Hachemi is also challenging a Canadian state immunity law that restricts the conditions under which a foreign government can be sued.
Some legal observers say Mr Hachemi has a strong case and point to provisions in Canada's constitutional charter of rights, reports the BBC's Lee Carter in Toronto.
However, lawyer James Wood, representing the Iranian government, told the court in Montreal that neither Iran nor its officials could be sued under Canada's State Immunity Act.
"Would Canadian (courts) accept that Polish citizens be allowed to take legal action against the Canadian government for the death of Robert Dziekanski?" Mr Woods asked.
This was a reference to the Polish immigrant who died in October 2007 after being shot five times by a police officer using a Taser stun gun at Vancouver airport.