Iran has ruled out a potential prison swap involving an Iranian-Swedish academic who has been sentenced to death for spying.
Ahmadreza Djalali has been held in Iran since 2016 and is due to be executed by 21 May.
He was accused in 2017 of having passed information on two Iranian nuclear programme officials to Israeli intelligence services.
His execution has alarmed Stockholm and led to reports of a possible swap with Hamid Nouri, a former Iranian prison official currently on trial for war crimes in Sweden.
But on Tuesday, a spokesperson for the Iranian judiciary ruled out any potential exchange and said the trial of Nouri was "politically motivated" and "illegal".
"The two cases have nothing to do with each other ... therefore, there is no question of an exchange", Zabihollah Khodayian told a press conference in Tehran.
Nouri was arrested in 2019 and is accused of involvement in the executions of thousands of prisoners in 1988 at the end of the Iran-Iraq war.
The verdict in the trial -- which has further strained relations between Stockholm and Tehran -- is due in mid-July. Nouri faces a life sentence if found guilty.
Meanwhile, Djalili is a Swedish-Iranian physician who specialises in disaster relief and has taught at European universities.
Rights groups have condemned his detention, saying it follows a pattern of Iran detaining dual nationals and expatriates indefinitely without due process.
On Twitter, Swedish Foreign Minister Ann Linde said the reports that Iran may carry out the death penalty were “very worrying” and called for Djalili's immediate release.
“We have said this several times to representatives of Iran,” she wrote, adding Sweden was in contact with Tehran.
Last week, a Swedish national was also arrested in Iran just after the EU member state warned against unnecessary travel to the country.