The families of two Austrian citizens currently imprisoned in Iran have written an open letter to the Austrian foreign minister Alexander Schallenberg demanding he does more to try and secure their release.

Massud Mossaheb and Kamran Ghaderi are both serving ten-year sentences, having been convicted on spying charges.

The families say Schallenberg has not made any public request regarding their release, nor complained about their detention or the torture the men have allegedly suffered. They say Schallenberg should demand that Tehran releases them immediately.

“We relatives are disappointed by the way the Austrian Foreign Ministry is treating the cases of Dr Mossaheb and Dr Ghaderi,” they say in the letter, adding that Schallenberg’s silence until now is “a sign of resignation, a lack of commitment or a lack of will to consider alternative strategies.”

There is an opportunity for Schallenberg to try and advance their causes this week, as Austria is hosting a series of meetings aimed at reviving the 2015 Iran nuclear deal. Iranian officials are in Vienna for the talks, alongside other signatories to the nuclear deal: China, the European Union, France, Germany, the U.K., the U.S. and Russia.

As part of that process, Schallenberg held talks with Iran’s deputy foreign minister Seyyed Abbas Araghchi. An Iranian report described the meeting as being held in “an amicable atmosphere”, but made no mention of either jailed man.

The Austrian Foreign Ministry has not yet responded to an enquiry for this article asking whether Schallenberg had raised the case of Mossaheb and Ghaderi at the meeting.

Ghaderi, an Iranian-Austrian dual national, was arrested in January 2016 during a business trip and was sentenced in October that year. Mossaheb, another Austrian-Iranian dual national, was detained in January 2019 while part of a delegation from an Austrian research centre. He was jailed in August that year, having been convicted of spying for Israel and Germany.

Amnesty International has described the two trials as “grossly unfair”. Their families say both men were denied legal counsel and made false confessions under torture and have only been spared the death penalty “as a means of pressure for negotiations.”

Both men are being held in Tehran’s Evin prison and 74-year-old Mossaheb is reported to suffer from a number of serious health conditions, including heart failure and diabetes.

Iran does not recognize dual citizenship, which limits what other governments can do for their dual citizens held there. The complaints of the two Austrian men’s families echo similar criticisms levelled at the UK government by dual British-Iranian nationals held in Iranian jails, including Nazanin Zaghari-Ratcliffe.

Campaigners accuse Iran of effectively holding foreigners and dual nationals as hostages and have previously called on governments to take action via the United Nations.