Abdolfattah Soltani, a lawyer representing the family of an Iranian-Canadian photojournalist who died in Iranian custody, was arrested on Saturday by five agents from the Tehran prosecutor’s office, said Mohammad Dadkhah, Soltani’s attorney.

“He has revealed information on nuclear spies both inside and outside Iran as well as to families of the suspects,” said Jamal Karimirad, Iran’s judiciary spokesman. “Soltani shouldn’t have revealed what he knew.”

Soltani, one of the lawyers representing the mother of photographer Zahra Kazemi, was taken into custody while at the headquarters of the Lawyers’ Association of Iran, Dadkhah said. The attorney was protesting the surprise inspection of his home by judiciary agents last week, Dadkhah said.

Last year, Iran said it detained several Iranian nationals who it accused of transferring nuclear secrets to foreigners. The suspects have been since tried but Iran has kept the verdicts a secret.

Dadkhah said he suspected the true reason for Soltani’s arrest was his provocative work investigating the case of Kazemi, who died in prison under suspicious circumstances. Last week, in an appeal related to the case, Soltani demanded hardline prosecutor Saeed Mortazavi appear for questioning.

An appeals court reviewed the Kazemi case last week but has not yet issued a verdict. In 2004, a court rejected a request to summon Mortazavi.

Kazemi died in jail in July 2003 about three weeks after being detained for taking photographs outside a Tehran prison during anti-government protests. Lawyers of her family believe she was beaten to death.

The case has soured relations between Iran and Canada, which is campaigning to determine the cause of Kazemi’s death.

Hard-line Iranian authorities say the photographer died of a stroke, but a commission appointed by Iran’s president found she died of a fractured skull and brain hemorrhage that were caused by the impact of a hard object.

Iran has repeatedly rejected Canadian requests for an international forensic team to examine the body, saying its judiciary is competent enough to carry out an investigation.

Also last week, Iran’s judiciary made the unprecedented acknowledgment that there were widespread human rights violations in the country, including arrests without sufficient evidence.