A former hostage negotiator, who secured the release of seven hostages in Iran 40 years ago, has appealed to the regime’s leadership to release British-Iranian prisoner Anoosheh Ashoori. Terry Waite, 80, has written a personal letter to Iran’s Supreme Leader Ayatollah Ali Khamenei to “show mercy and compassion” by releasing Mr Ashoori to his family. Mr Ashoori, a retired engineer, was arrested in Iran in 2017 while visiting his mother and jailed for 12 years after the Iranian authorities accused him of spying for Mossad. He denies the accusations against him. He is being detained in Tehran’s Evin Prison in a ward where coronavirus victims are believed to have been held. Mr Waite previously served as the British Special Envoy to the Archbishop of Canterbury and negotiated the release of Christian hostages in Iran in 1980. He writes in his letter, seen by <em>The National</em>, that his visit took place when diplomatic relations between the UK and Iran had ceased but he was still treated "with the greatest courtesy by the Revolutionary Guards". “After prolonged discussions, the men and women, both UK and Iranian nationals, who had been detained were released to my care and were able to return to their own homes,” the letter reads. “All I can do at this time is to respectfully request that the authorities in Iran demonstrate once again, as they did to me many years ago, the true spirit of Islam and show mercy and compassion by releasing Mr Anoosheh Ashoori to his family,” he wrote. Mr Waite said he wished he could visit Iran again to discuss Mr Ashoori’s case but his age and the current situation prevents this. "If I was much younger, I would have liked to have been able to go out there and meet with people as I did years ago," he told <em>The National</em> over Skype. Mr Waite has visited Evin Prison, which he described as “not an attractive place”, where Jean Waddell, secretary to an Iranian Anglican bishop, was imprisoned. As well as securing the release of Ms Waddell and other hostages in Iran, five years later he went on to negotiate with Muammar Qaddafi to win the freedom of four British hostages in Libya. Mr Waite has intervened in a personal capacity to support Mr Ashoori’s family. He has a unique understanding of Mr Ashoori’s situation because he was himself kidnapped in Lebanon in 1987. He was held captive by Islamic Jihad while attempting to free several western hostages being held by the Shiite militia. “I had almost five years in solitary confinement. It’s not pleasant,” he recalled. “I think it’s particularly difficult being in that prison [Evin] because you are thrown together with all sorts of other characters. I was alone, which in some ways was a blessing.” Mr Waite said those negotiating on behalf of Mr Ashoori and other dual nationals jailed in Iran should not underestimate the value of establishing personal relationships with the Iranian authorities. “So much of our contact has been at a remote formal diplomatic level, which doesn’t get to the heart of the matter," he said. "You have to meet with people and you have to sit with them and understand their way of working. You have to be sympathetic to that without necessarily agreeing with what they do. That, I believe, is sometimes missing in all of this.” The Iranian ambassador to the UK claimed earlier this week that bilateral talks were under way to resolve a £400 million debt cited as an obstacle to the release of dual nationals held by the regime. On Tuesday, British charity worker Nazanin Zaghari-Ratcliffe was allowed to leave Evin Prison for two weeks with an ankle tag as Iran tries to halt the spread of coronavirus in the country. Mr Ashoori's wife Sherry Izadi is concerned that Ms Zaghari-Ratcliffe's temporary release will lead to her husband and other dual nationals' <a href="https://www.thenational.ae/world/europe/family-of-iran-prisoner-anoosheh-ashoori-call-on-uk-government-not-to-forget-him-1.994256">cases being forgotten.</a> Dominic Raab, the UK’s Foreign Secretary, told MPs on Thursday that he had made it “absolutely clear” to his Iranian counterpart Mohammad Javad Zarif that all dual nationals should be released. He said he was hugely relieved at the temporary release of Ms Zaghari-Ratcliffe but said it was only a step forward. The UK would not “pause for breath until all dual nationals are released,” he said.