A Swedish court is expected to deliver its verdict on Thursday in the war crimes trial of former Iranian prison official Hamid Nouri, who is accused of complicity in the deaths of thousands of prisoners more than 30 years ago.
The politically sensitive trial surrounds a wave of executions which allegedly took place in 1988 as the Iran-Iraq war was coming to a close but for which nobody has ever been tried until now.
Estimates of the death toll vary but human rights groups have put the number between 3,000 and 30,000 and described the victims as political prisoners condemned after sham trials.
The court heard during nine months of hearings that Mr Nouri worked for a senior prison official at the time and was involved in handing down death sentences and bringing prisoners to an execution chamber. He denies the charges of murder and war crimes.
The Swedish prosecutors and regime opponents claim that the late Ayatollah Ruhollah Khomeini, the former Iranian supreme leader, ordered the executions and current Iranian President Ebrahim Raisi is under US sanctions because of his alleged role as a prosecutor in Tehran.
A group of UN special rapporteurs reported in 2020 that the families of those missing had never been told about the fate of their relatives or the whereabouts of their remains.
Their letter spoke of a "systemic impunity" enjoyed by those behind the alleged killings and said the Iranian regime had played down the number of deaths, even claiming many died in fighting.
“The massacre of 1988 is in the DNA of the clerical regime,” said Shahin Gobadi, a spokesman for the People’s Mujahideen Organisation of Iran, an opposition group based in France, which advocates the overthrow of Iran’s leaders.
The court heard many of the victims of the alleged massacre were members of the exiled mujahideen group, also known as the MEK.
The opposition had worked with the Iraqi army to carry out attacks during the eight-year conflict with Iran, Swedish prosecutors said — which is what brings the deaths of prisoners into the territory of alleged war crimes.
Some of the cases are being tried as murder, rather than violations of international law, because the Iranian leadership allegedly decided to widen the round-up to include left-wing sympathisers and people who had renounced their faith.
“Nouri is a criminal in mass scale but he is a low-ranking official of the regime who was involved in the massacre,” Mr Gobadi said. “It is time that they be held accountable and brought to justice.
“The Iranian resistance that has started this campaign since August 1988, will continue its campaign until they are brought to justice.”
The prosecutors in Sweden called for a life sentence for Mr Nouri after telling the court they had 58 witnesses attesting to his presence.
He denies involvement, saying he worked at a different prison and was on leave at the time in question.
“I hope these hands will be cleared ... with the help of God," Mr Nouri told the court via an interpreter, his palms raised to the sky, at the end of the hearings in May.
The defence also objected to Sweden’s claim to be able to try people for war crimes and other grave offences wherever they happened in the world, under a principle called universal jurisdiction.
Tehran protested to the Swedish government that Mr Nouri’s arrest was illegal and the Foreign Ministry in Stockholm advised its citizens against travelling to Iran if they could avoid it.
The trial coincided with a death sentence handed down in Iran to Iranian-Swedish academic Ahmadreza Djalali, whom Amnesty International described as being held as a hostage.
Iranian opposition figures in Sweden had filed complaints against Mr Nouri which led to his arrest at a Stockholm airport in November 2019.
The court heard evidence during 93 sessions, including two full days of evidence by Mr Nouri, after which he was cross-examined by prosecutors.
The trial was briefly relocated to Albania at one stage to hear evidence from witnesses unable to travel to Sweden.
Opponents of the Iranian regime held regular protests outside the courtroom in Stockholm and another rally is expected on the day of the verdict.