Moderate former president Mohammad Khatami rejected as a "show" the trial of 100 prominent reformers who were arrested after Iran's disputed June presidential poll set off unrest, his website said on Sunday.
Iran tried on Saturday 100 moderates arrested shortly after Iran's June 12 election, charged with trying to overthrow the clerical establishment.
"The trial on Saturday was a show and the confessions are invalid ... What was called a trial was a violation of the constitution," his website khatami.ir reported.
"Such show trials will directly harm the system and will further damage public trust."
It was the first time since Iran's 1979 Islamic revolution that dozens of senior officials, including former ministers, vice-president and lawmakers, had been put on trial.
The official IRNA news agency said the defendants were charged with rioting, attacking military and government buildings, having links with armed opposition groups and conspiring against the ruling system.
Khatami, who backs moderate defeated candidate Mirhossein Mousavi, said detainees had confessed under duress.
"These confessions have been taken under extraordinary conditions. The detainees were not informed in advance about the court session and lacked access to lawyers," Khatami said.
"PUNISHMENT"
State television showed footage of the courtroom with many young defendants, some handcuffed, and vice-president Mohammad Ali Abtahi, former deputy foreign minister Mohsen Aminzadeh and former MP Mohsen Mirdamadi in prison uniform.
Leading moderates say the vote was rigged in favour of hardline President Mahmoud Ahmadinejad. The authorities deny the charge and Iran's Supreme Leader, Ayatollah Ali Khamenei, has endorsed Ahmadinejad's re-election.
Khamenei will formally approve on Monday Ahmadinejad's second four-year term. He will be sworn in before parliament on Wednesday. Leading moderates have denounced the new government as "illegitimate".
State television showed two prominent reformers saying that the vote was not rigged. Abtahi, a close ally to Khatami, apologised for his misjudgements about the vote.
Abtahi also testified that leading moderates Mousavi, Khatami and former president Akbar Hashemi Rafsanjani had taken an "oath" before the vote to support each other, IRNA reported.
Rafsanjani, who heads the Assembly of Experts that can appoint or dismiss the supreme leader, denied it. The election has created a rift among senior Iranian officials.
Mousavi and the authorities blame each other for the bloodshed. At least 20 people died in violence after the poll.
Conservative defeated candidate Mohsen Rezaie urged Iran's top judge to punish "those who violated the law by attacking and killing" protesters, the semi-official Mehr news agency said.
Mohsen Ruholamini, the son of an adviser to Rezaie was reported dead in Tehran's notorious Evin prison by Iranian media after being detained in post-election unrest.
"Those behind the murder of my son should be punished," said Abdolhossein Ruholamini on Sunday, Mehr reported.
Rights groups say hundreds of people, including senior pro-reform activists, journalists, academics and lawyers, have been arrested since the vote.