MONTREAL - The son of slain Iranian-Canadian photojournalist Zahra Kazemi sent a stinging letter Friday to the prime minister criticizing the federal government's handling of the seven-year-old case.

Stephan Hashemi accuses the government of consistently uttering empty words of condemnation while failing to back them up with any concrete action against Iran.

In a letter to Prime Minister Stephen Harper dated Friday, Hashemi notes that the government is even working against him in a Canadian court case he launched against Iran.

"Successive governments in Ottawa, yours and your predecessors', have, for six and a half years, proclaimed their indignation over the actions of the government of Iran," Hashemi wrote.

"(Yet) your government continues to oppose the judicial proceedings which I have launched here in Montreal."

His letter to Harper comes as a Quebec civil trial pitting the Kazemi estate against the Iranian government is set to wrap up Monday.

Hashemi wants Ottawa to stop defending the State Immunity Act, legislation that forbids foreign governments from being sued in Canada for crimes against humanity, including torture.

The estate and family of the late photographer filed a $17-million civil suit over her detention, torture and slaying in 2003.

Federal lawyers have responded in court by saying the immunity act should apply in the case, while Iran's lawyers cite that very act to argue that they are immune from prosecution in Canada.

The government said in a statement that it has demanded a "transparent and credible investigation" of those implicated in Kazemi's murder and that it remains a key issue in Canada's relationship with Iran.

"To be perfectly clear, the Government of Canada is in no way defending the Iranian regime," said Catherine Loubier, a spokeswoman for Foreign Affairs Minister Lawrence Cannon.

"We have been consistent in speaking out against the flagrant human rights abuses of the government of Iran, including leading the charge calling for a UN investigation into the actions of the Iranian regime."

Loubier said Canada has been vocal in condemning the crackdown on the pro-democracy movement following disputed presidential elections, and also led a walkout on Iranian President Mahmoud Ahmadinejad at the UN.

But Hashemi said the Canadian government has not done enough to pursue justice in the case.

He launched his Quebec civil suit against the Islamic Republic of Iran; its leader, Grand Ayatollah Ali Khamenei; former Tehran prosecutor Saeed Mortazavi; and prison official Mohammad Bakhshi.

As it stands, the State Immunity Act only allows states to be sued in civil court under very strict conditions, and with very few exceptions other than suits for commercial purposes.

"I would like to ask you: what was my mother's citizenship worth if those responsible for her death cannot be called to account for their actions before a Canadian court?" Hashemi wrote.

He also demanded that Canada haul Iran before the International Court of Justice and that international arrest warrants be issued for those involved in his mother's death.

And he also renewed his long-standing position that Kazemi's body be repatriated to Canada.

"If the doors to the courts of Canada are closed to us, there will no longer be any place in which to obtain this much sought justice, since the Iranian justice system has proven, many times over, its powerlessness and incompetence in this matter," Hashemi wrote.

Kazemi, 54, was an Iranian-Canadian citizen who was arrested on June 23, 2003, as she photographed relatives of detainees outside Evin prison in Tehran.

She was never formally charged with any crime, but while in custody she was beaten. She died of her injuries on July 10, 2003, and subsequent reports stated she was sexually assaulted, badly beaten and tortured.

Ottawa has had shaky relations with Iran since Kazemi's murder and has routinely voiced its displeasure with officials in that country over the handling of the case and their lack of transparency.