The spokesperson confirmed that Austrian Foreign Minister Alexander Schallenberg has written to his Iranian counterpart – Mohammad Javad Zarif – and said that the country’s embassy in Tehran has been actively participating in the case.

However, he also explained that the Iranian government does not recognise dual nationality meaning that he is not automatically entitled to consular assistance.

The Der Standard newspaper reported that Massud Mossaheb had gone to Iran to visit a new subsidiary of an Austrian research centre. He travelled to Tehran with a delegation of colleagues.

His family were left without any news about him for several weeks. They were eventually informed that he was being held in the notorious Evin Prison in the country’s capital.

The Austrian foreign ministry said that the reason for Massud Mossaheb’s detention is unknown and that he has not been formally charged with anything. The spokesperson also said that it has emphasised to the Iranian government that Massud Mossaheb is suffering from health problems and is in his seventies, therefore the humanitarian aspect of his imprisonment should be carefully considered.

Also being held in Evin Prison is British-Iranian dual national Nazanin Zaghari-Ratcliffe. She was introducing her young daughter to her family in Iran in 2016 and was arrested in the airport as she was about to return to Britain.

The Iranian regime has accused her of attempting to topple the country’s government. She has been held in very poor conditions and security agents have tried to force a false confession out of her. She has been sentenced to five years in prison.

Her husband, Richard Ratcliffe, and a number of other people with family members locked up abroad, have called on the British government to do more to protect British citizen’s abroad. In a letter to the new British Prime Minister Boris Johnson, they said that they want past mistakes corrected so that the rights of all British citizens are protected.
They also said in their letter: “ It should not be the choice of the foreign secretary to act to protect a British citizen abroad but rather the obligation.”

Mr. Ratcliffe said that he expects his wife’s case to be a priority and said that he is frustrated by Johnson’s failure to take responsibility after he falsely said during an interview that Nazanin was in Iran to teach journalism. Mr. Ratcliffe said that although Johnson was not responsible for her being arrested, he did contribute to where she is now.

Many believe that the Iranian regime is arresting and imprisoning dual nationals because it want to have leverage over foreign countries.