It was on Saturday, shortly after lunchtime, that the man was arrested at Arlanda Airport, the police spokesperson reports to SVT News in an email.

The 58-year-old man was arrested in his absence and arrested immediately upon arrival, police say. He has now been remanded in custody and is suspected of violating international law committed July 28 to August 31, 1988 in Karaj, Iran.

The man's lawyer does not want to comment on the case at this time.

- The only thing I can say is that this is not a common goal, says lawyer Lars Hultgren.

Systematic executions around the country

Iran had a tumultuous ten-year period that began in 1978. As soon as the mass protests in the country had led to a revolution involving both regime and state change, Iran was attacked by neighboring Iraq and thrown into an eight-year long war.

Just before the end of the war, thousands of politically opposites were subjected to both enforced disappearances and systematic executions during the summer of 1988, writes the human rights organization Amnesty International.

The executions must have taken place in at least 32 locations around the country, including in Karaj. That is, the same period that the 58-year-old man is suspected of having committed international law.

- It is estimated that there may be up to 5,000 people executed, while there are those who claim that there are even more. And this happened for almost three months from July 1988, says Rouzbeh Parsi, program director at the Foreign Policy Institute of the Middle East and North Africa Program.

Over 30 years ago

According to Rouzbeh Parsi, it is not entirely clear who initiated these executions described as a dark spot in Iran's post-revolutionary history.

- What we do know is that Khomeini himself issued two fatwor to review the judgments that already existed. So these were not people who were arrested then, but who were already in prison and had already been sentenced, says Rouzbeh Parsi.

Iran has not officially acknowledged these abuses, even though it has been over 30 years. But they also did not deny the executions. And relatives around the world continue to seek answers and command justice.

"Iran has never said that it has not happened, but they also do not talk about how things went and how many there are," says Rouzbeh Parsi.

The text is updated