Iran's defeated opposition¹ presidential candidate has said that some protesters held after last month's disputed poll were tortured to death in prison.

伊朗总统竞选败北的反对党候选人称，上个月具有争议的竞选之时的反抗者有的在监狱中被折磨致死。

Mr Karroubi urged Tehran to review his evidence in "a calm atmosphere"

The claim by Mehdi Karroubi comes days after he said a number of prisoners, both male and female, had been raped³.

Officials deny the rape² claims, but admit that abuses have taken place.

The BBC's Jon Leyne says the opposition uses the issue to maintain political pressure without directly questioning Mahmoud Ahmadinejad's poll victory.

On Thursday, Mr Karroubi alleged⁴（被说成的，被指称的） that a number of detainees（被拘留者，未判刑囚犯） had been tortured to death.

"Some young people are beaten to death just for chanting slogans in [post-election] protests," his website said.

Mr Karroubi also called for the formation of an independent committee to review his evidence in "a calm atmosphere".

On Sunday, the defeated presidential candidate claimed that some opposition protesters were raped in detention⁵.

The claim was supported by a number of human rights groups but quickly dismissed as "totally baseless" by the speaker of Iran's parliament, Ali Larijani.

"Based on parliament's investigations⁶, detainees have not been raped or sexually abused in Iran's Kahrizak and Evin prisons," said.

Mass protests

The conditions under which detained protesters have been held has been controversial, with damaging claims forcing authorities to act.

The Supreme⁷ Leader, Ayatollah Ali Khamanei, closed the notorious（臭名昭著的） Kahrizak detention centre saying it had failed to "preserve（保护，维持） the detainees' rights".

Police officials have admitted that some of those held since June might have been tortured.

Both the Iranian parliament and judiciary have established committees to investigate the post-election unrest and the government's response.

BBC Tehran correspondent Jon Leyne says the issue of prison abuse is both a real concern in itself and also has become a way of criticising the government of President Ahmadinejad without directly challenging the legitimacy⁸（合法，适当） of his re-election.

On Tuesday, Iran's authorities said 4,000 people had been detained during the mass protests that broke out in the wake of the 12 June presidential poll, which the opposition says was rigged.

The number was much higher than previous figures, although the authorities said 3,700 of them had been released within a few days of arrest.

Opposition leaders say 69 protesters died in the post-election violence - more than double the official figure of about 30 fatalities⁹.

Trials criticised

Iran is currently trying more than 100 detainees over their alleged involvement in the protests.

The trials - of leading opposition figures, activists¹⁰, journalists, lawyers, workers at foreign embassies and two people with foreign nationalities - have been criticised by several foreign powers, opposition groups and human rights campaigners.

But authorities insist their legal proceedings¹¹ are completely legitimate¹² and conform to international standards of justice.

Official election results awarded incumbent¹³ President（现任总统） Mahmoud Ahmadinejad a sweeping¹⁴ victory in the polls.

He is in the process of selecting a cabinet, which will be submitted to parliamentary approval next week.

Foreign media, including the BBC, have been restricted in their coverage¹⁵ of Iran in the wake of the election protests.