The European Commission said it was "very worried" about a Swedish EU official who has spent more than 500 days in jail in Iran.
EU Commissioner Ylva Johansson expressed her concern about Johan Floderus, who has been detained for more than 500 days in Iran on espionage charges.
"I'm very sad. I'm very worried. And this has been with me for such a long time now," she said.
Floderus, who worked for the European Union's External Action Service, was arrested in April 2022 at the Tehran airport while returning from a leisure trip with friends.
On Sunday, Floderus turned 33 behind bars in Evin Prison.
"He was a very bright, very warm, and an excellent person to work with. And, of course, when you work close, you also become friends," said Johansson.
Floderus had been on Johansson's team for two years, but he had moved to another group because he wanted to work for the EU delegation in Afghanistan.
"Of course, my feelings and my worries are nothing compared to the situation of Johan or the worries that his closest family are living with every day," she said.
Two weeks before Floderus' arrest, an Iranian was sentenced to life imprisonment in Sweden for his role in the mass executions carried out by the Iranian regime in 1988.
Floderus' family said he has been held in "unacceptable" conditions, saying he is in 24-hour lighting in his cell.
"His need for adequate food rations, outside walks, medical checkups, and much more are not respected," the family added.
The family announced that he made a desperate appeal in a rare video call last month for more efforts to release him.
Family and friends have started a public campaign for urgent international attention to ensure his immediate release and safe return to Europe.
The EU did not confirm that Iran was detaining one of its diplomats until the New York Times reported the news earlier this month.
It was previously confirmed that a Swedish national was detained in Iran without mentioning his position in the European Union.
The European Union's foreign policy chief, Josep Borrell, said last week they were doing everything they could to negotiate Floderus' freedom.
Borrell noted that the Swedish government was responsible for getting him home from Iran, but the EU supported it.
Reuters quoted his family saying Floderus had traveled throughout the Middle East to study languages, explore historic sites, and support humanitarian cooperation projects in Iran on behalf of the EU, and was arrested in April 2022 before leaving the country.
The Iranian Revolutionary Guard Corps (IRGC) has recently detained dozens of dual nationals and foreigners, most of whom faced espionage charges.
Human rights activists accuse Iran of detaining foreigners to pressure other countries to make concessions.
Iran and the US reached an agreement that includes the release of five US citizens detained in Iran and releasing frozen Iranian assets in South Korea worth $6 billion.
On August 10, Tehran transferred four US citizens from Evin Prison to a hotel, under house arrest. They join a fifth citizen already under house arrest in the first step of an agreement under which the five will eventually be allowed to leave Iran.
