TEHRAN (Reuters) -- Iran's defeated presidential candidate Mehdi Karubi has said on his website that some of those arrested after the June presidential election were tortured to death, but other inmates defended their treatment.
Authorities were not immediately available for comment, but state television, in a report on a parliamentary committee investigating claims of prison abuse, has shown people testifying that they were treated properly.
"I am not under pressure. I am satisfied with the conditions provided by the jail authorities," said a young detainee in Tehran's Evin prison, where many political prisoners are held.
Expanding on allegations he made on August 9 that some arrested protesters, men and women, had been raped at Tehran's Kahrizak prison, Karubi said on August 13 detainees had reported being forced to go naked, with prison guards riding on their backs.
Still others were piled on top of each other, also naked.
"We observe that in an Islamic country some young people are beaten to death just for chanting slogans in [the postelection] protests," Karubi's Etemademelli website said.
"Some of the detainees said they were forced to take off their clothes. Then they were made to go on their hands and knees and were ridden [by prison guards]," Karubi said.
"Or the prison authorities put them on top of each other while they were naked," he added.
His allegation about prisoners in Kahrizak prison being raped was rejected by Iranian authorities as "baseless."
Many of the posteection detainees were held in the south Tehran prison, built to house people breaching vice laws. At least three people died in custody there and widespread anger erupted as reports of abuse in the jail spread.
Supreme Leader Ayatollah Ali Khamenei ordered the closure of the Kahrizak prison last month.
The abuse allegations, also rejected by Tehran's police chief, have created a rift among hardline politicians, many of whom backed President Mahmud Ahmadinejad's reelection.
The disputed election was followed by the worst unrest in Iran since its 1979 Islamic Revolution.
'President's Word Like God's'
A senior Iranian cleric seen as Ahmadinejad's spiritual mentor said obeying the head of government was like obeying God, the moderate "Etemad-e Melli" newspaper said.
Firebrand cleric Ayatollah Mohammad Taqi Mesbah-Yazdi believes the authority of Khamenei comes from God, not from the people.
Khamenei presides over a complex political and clerical system known as vali-ye faqih, or religious jurisprudence, with the president in charge of the day-to-day governing of the country.
"When a president is endorsed by the vali-ye faqih, obeying the president is like obeying God," the daily quoted Mesbah-Yazdi as saying.
Mesbah-Yazdi's followers have great sway among Iran's elite Revolutionary Guard and the Basij volunteer paramilitary force.
The Guard's political chief Yadollah Javani has called for defeated candidates Karubi and Mir Hossein Musavi as well as moderate former President Mohammad Khatami to be put on trial for inciting election unrest.
At least 200 people still remain in jail, including senior moderate politicians, activists, lawyers and journalists.
Khamenei swiftly endorsed Ahmadinejad's reelection after the June 12 presidential vote.
The losing candidates say the poll was rigged, a charge denied by Iran's authorities, including Khamenei, who has accused Western powers of fomenting the vote unrest.
Moderates say 69 protesters were killed in the demonstrations, contradicting the official report of 26 deaths.
Frenchwoman's Release Expected
Iran's police and security forces quelled the protests and the judiciary has now begun mass trials of more than 100 moderates, despite the damage it might inflict on the government's legitimacy and relations with the West.
The United States, its European allies, and Iranian moderates have denounced the mass trials as a "sham."
Among those being tried are French teaching assistant Clotilde Reiss and two employees of French and British embassies in Tehran, accused of espionage and taking part in a Western plot, charges France and Britain say are baseless.
Reiss's father said on August 13 he hoped his daughter would leave prison later in the day, after France agreed to provide bail for her conditional release.
The fallout from the postelection unrest further clouds prospects of Iran accepting U.S. President Barack Obama's offer of direct talks on Iran's nuclear programme. Tehran denies that it has nuclear arms ambitions.