Johan Floderus, who has been held in Iran since April 2022 and faced the death penalty on spying charges, and Saeed Azizi, who was arrested in November 2023, were on a flight to Sweden "and will finally be reunited with their relatives", Kristersson said in a statement.

The announcement coincided with a statement from Iran that Hamid Noury, a former Iranian prison official jailed for life in Sweden, had been freed and would return to the Islamic republic soon.

Kristersson said Iran had made Floderus and Azizi "pawns in a cynical negotiation game, with the aim of getting Iranian citizen Hamid Noury released from prison in Sweden".

Noury, a 62-year-old Iranian former prison official, is serving a life sentence in Sweden for his role in mass executions in Iran in 1988.

"As Prime Minister, I have a special responsibility for the safety of Swedish citizens. The government has therefore worked intensively on the issue, together with the Swedish security service, which has negotiated with Iran," he said.

"It has been clear all along that the operation would require some difficult decisions. Now we have made those decisions."