A Dubai-based businessman jailed in Iran has urged the head of the country’s judiciary to stop “destroying” him and his family after four years behind bars. Siamak Namazi, 48, said a disgraced relative of a senior official was granted temporary release from jail within hours of arriving, while he has been detained despite repeated requests, said a letter seen by the US-based Centre for Human Rights in Iran. Mr Namazi was jailed for 10 years for espionage for what his family claim were trumped up charges. His father, Baquer Namazi, 83, was also jailed after travelling to the country to see his son but has been allowed to leave prison because of poor health. He is unable to leave Iran. In a letter to the head of the Iranian judiciary, Mr Namazi said that after a year of submitting temporary release requests he was granted one five months ago – but has still not been allowed out. “I ask that you issue an order to the authorities to stop trying to destroy me and my family and observe the laws concerning security prisoners and recognise my rights,” he said in the letter. “It is my request and expectation to be granted furlough for a few weeks, as I am deserving of it,” Mr Namazi wrote in the letter, which was first published on the Telegram messaging channel of Iranian news site Ghanoon. “This would create an opportunity to repair my poor mental and physical state and allow me to help my 83-year-old father recover from a life-threatening illness and rectify my family’s deplorable situation.” The father and son are among at least 11 dual nationals currently detained in Iran. Rights campaigners say the figure is likely to be higher as Iran and foreign governments discourage families from publicising their cases. Siamak Namazi, a US-Iranian joint national who had lived in the UAE since 2007, was arrested in Iran two years after publishing an article critical of the US sanctions regime, saying it prevented the flow of medicine and medical equipment to Iran. The businessman has spent periods in solitary confinement at Evin jail and was not allowed to see his father, who was arrested the following year. He was convicted in October 2016 along with his father, a retired UN official, for collaboration with a hostile government in a trial that lasted only a few hours. Their family was given hope with the release of a US student, Xiyue Wang, in a prisoner exchange in December. But the killing of Iran’s most powerful general, Qassem Suleimani, the following month has reduced the prospects of further releases, said Iran’s Foreign Minister Javad Zarif. Other prisoners have been allowed out temporarily, including Nazanin Zaghari-Ratcliffe, who has been held since April 2016. She was released for three days in 2018 to visit her parents and daughter, but was ordered to return to Evin.