The health of long-time Iranian political prisoner, Farhad Meysami, who has lost a lot of weight due to his hunger strike, has deteriorated.

A photo of Meysami along with a letter from Rajaei-Shahr prison in Karaj were published on social media Thursday, showing him in a horrible condition after losing weight.

However, the political activist wrote in the letter to prison officials that “I will still insist on my three demands of stopping the execution of protesters, releasing six political prisoners, and stopping mandatory hijab.”

The title of political activist's letter is "For the days of suffering and suffering and suffering".

Farhad Meysami, who has been behind bars since August 2018 was arrested and sentenced to six years in jail for his activism against mandatory hijab.

Last month, in a message from Rajaei-shahr prison, he demanded the immediate release of several civil and political activists.

Meysami also went on a hunger strike in May in protest to the possible execution of Ahmadreza Jalali, a Swedish-Iranian dual national scientist taken hostage since 2016 was under the threat of execution last year.

Meysami later announced that he has ended his two-week hunger strike as Ahmadreza Jalali was not executed. Before the end of that hunger strike, his physical condition was so critical that he was transferred to hospital.

Meysami, a doctor and teacher, said in a message last year that he had met Djalali at Tehran's Evin prison over three years earlier. "He had been on hunger strike in protest to repeated threats of his execution and the effects of which on his body and soul were clearly visible," he wrote.

"Imagine subjecting a human being to this repeatedly. Not once, not twice… Is there any torture worse than this?" Meysami said about repeated threats of execution made against Djalali.

"I don't want to just oppose Dr Djalali's execution, I want to draw attention to something much more important, to draw attention to the fact that they send a man to his death many times and bring him back," he wrote. "Regular and intentional torture like this is definitely crime against humanity."

Meanwhile, famous Iranian filmmaker Jafar Panahi has also gone on a hunger strike to protest his detention in Tehran while his sentence has been declared void by the country’s Supreme Court.

“I firmly declare that in protest against the illegal and inhumane behavior of the judicial and security apparatus and their hostage-taking, I have started a hunger strike since the morning of February 1… I will refuse to eat and drink any food and take medicine until the time of my release,” read a statement he sent to his wife.

Iran has been the scene of nationwide protests against the clerical regime after the death in custody of Mahsa Amini in mid-September.

Authorities have not released any information on the number of detainees, those injured and killed in the protests that began nearly three weeks ago following the death in custody of Mahsa Amini who was arrested for not wearing her hijab “properly”.

Human rights organizations says that nearly 520 protesters, including children, have been killed by security forces during the protests.