A political prisoner has called on Iran's chief justice to investigate his revelation that dissident rapper Saman Seydi (Yasin) was subjected to mock execution.

In an open letter addressed to Chief Justice Gholamreza Mohseni-Ejei Thursday, Ahmadreza Haeri has offered more details about the mock execution of a former fellow inmate Yasin, at Ward 240 of Tehran’s Evin Prison.

Yasin whose death sentence was overturned by the Supreme Court in December, in audio files smuggled from prison, has described severe torture including a mock execution during which he was forced to stand on a chair with a noose around his neck after being told to write his last will and testament.

“He is young. One must show mercy. Try to place the noose sideways so that his neck breaks right away when he drops so he doesn’t suffer too much,” Yasin says one of his supposed executioners said to the other.

Then, he says, there was a call after which he was told the execution had been delayed giving him “another chance to cooperate”. Two days later, a real death sentence was handed to him. His wife miscarried her eight-month baby after finding out about the death sentence.

Yasin (27) belongs to the persecuted Kurdish Yarsan religious community and was a vocal critic of the regime before his arrest for supporting the anti-government protests known as the Woman, Life, Freedom movement. He has only attended the court once during his fourteen months of imprisonment and does not have access to his lawyer.

“Form a fact-finding committee consisting of independent lawyers and judges to investigate this matter and allow independent journalists and reports to monitor the committee’s performance,” Haeri wrote.

Haeri alleges that Yasin was taken from his cell in the middle of night and subjected to a mock execution to force him to accept fabricated charges including the use of a combat weapon during last year’s anti-government protests, which would justify a death sentence sought by the prosecutor against him.

According to Haeri, tens of other prisoners heard Yasin’s account of the torture and mock execution he had undergone when he was taken back to the general ward, mentally and physically shattered.

Haeri, a lawyer and human rights activist, is serving a sentence at Ghezel Hesar Prison for exposing the beating of other prisoners at Tehran’s infamous Fashafouyeh Prison in 2014, which led to the death of two inmates, during an incident which came to be known as “Black Thursday”.

State-affiliated media such as the Revolutionary Guards (IRGC) linked Tasnim news agency claimed Wednesday that a new case has been opened against Haeri for not being able to provide proof for the claim in his letter earlier this week that Yasin was subjected to mock execution.

Many other political prisoners and prisoners of conscience have claimed that they were subjected to mock executions to extract confessions that would justify harsh sentences including Sahand Noor-Mohammad-Zadeh, 26, an anti-government protester.

He was accused of setting a trash bin on fire and blocking traffic, both of which he denied. But he had several times been blindfolded and told to climb a chair to be hanged before his trial. He was sentenced to death for moharebeh (enmity against God) and was executed on November 2 last year.

Another protester, Majid Kazemi, said he had undergone mock executions at least fifteen times, in addition to other tortures including upside down suspension and showing him a video of his brother being tortured to “confess” to whatever was dictated to him. Kazemi was also executed on May 19 for “enmity against God”.

In a statement on November 23, the US State Department condemned mock executions and torture of prisoners in Iran with the hashtag #SamanYasin and called on the Iranian authorities to immediately stop “these inhumane practices and conduct fair and transparent trials for their citizens.”