A medical researcher sentenced to death in Iran three years ago on a charge of spying, which he denies, is under threat of imminent execution, Nature has been told.

Ahmadreza Djalali, a scholar in disaster medicine who has dual Iranian-Swedish nationality, is nearing the end of a week of solitary confinement at Evin prison in Tehran, where he has been held since 2016. He was expected to be transferred to Rajai Shahr prison, west of Tehran, on Tuesday this week, where the execution could be carried out.

This information is contained in a letter dated November 24 that carries the name of Mohammad Barae, understood to be a judge in Iran’s legal system.

Vida Mehrannia, Djalali’s wife, told Nature she had received a telephone call from him on November 25 in which he said he was being moved to solitary confinement and then to a different prison to be executed.

“This letter looks to be a court order from a judge declaring that the death sentence is to be carried out,” says Ziba Mir-Hosseini, a scholar of Iran’s legal system based at SOAS University of London.

Djalali’s situation will not have been helped by the killing of Iran’s leading nuclear scientist, Mohsen Fakhrizadeh, on November 27 near Tehran, says Hadi Ghaemi, a physicist and founder of the Centre for Human Rights in Iran, a non-governmental organisation based in New York City.

Mahmood Amiry-Moghaddam, an Iranian-Norwegian neuroscientist who leads the NGO Iran Human Rights, based in Oslo, agrees that Djalali’s situation is very serious.

Sweden’s foreign ministry is urging clemency as are international observers. A spokesperson for Swedish Foreign Minister Ann Linde says the nation demands that the death penalty not be enforced.

The two countries are understood to be in talks regarding the case.

However, in a statement published by the BBC, Iran’s government says that media reports are incorrect and warns countries not to interfere in what it says is an independent judicial process.

Nature asked to speak to Iran’s justice and foreign-affairs ministries, but e-mails and calls were not answered.

Djalali, who worked for the Karolinska Institute in Stockholm, was arrested in 2016 on a research trip to Iran. He was charged with spying and was sentenced to death the following year by the Revolutionary Court, the body that hears the cases of people considered to be a threat to national security.

The case went to the Supreme Court, Iran’s highest court of appeal, but the judges declined to change the sentence of death.

The prosecution claims that Djalali received academic positions, research projects and funding in Europe in exchange for spying on Iran for Israel — a charge he has consistently denied. A document attributed to him says that he has been tortured in prison, and that he thinks he is being punished for refusing a request from Iran’s government to spy on Europe. He is also said to have undergone hunger strikes in protest.

He is being supported by a campaign by 153 Nobel laureates. In response to the latest developments, the group urged Iranian Supreme Leader Ayatollah Ali Khamenei to release him. The judiciary comes under the jurisdiction of the office of the supreme leader, Iran’s head of state.

“The attack on Ahmadreza Djalali is a tremendous assault to the academic community at large. It will have a chilling effect on international collaboration and trust,” says Karolinska president Ole Petter Ottersen.

Some observers say there is a possibility Djalali could be spared if Sweden’s government agrees to discuss a prisoner exchange, as other countries are doing.

Last week, Iran freed Kylie Moore-Gilbert, an Islamic-studies researcher at the University of Melbourne in Australia, who was arrested in September 2018 after attending an academic conference.

According to media reports, Moore-Gilbert was released in exchange for three Iranian citizens imprisoned in Thailand.

In March 2020, the French government released Jalal Rohollahnejad, an Iranian engineer affiliated with the Wuhan National Laboratory of Electronics in China, in exchange for Iran’s release of French sociologist Roland Marchal of the University Sciences Po in Paris.

In December 2019, the United States freed Iranian biologist Masoud Soleimani in exchange for the release of Xiyue Wang, a US historian held in Iran.

–              A Nature magazine report