The price of speaking out against the Iranian regime

Sky News understands Iranian doctor Yaser Rahmani-Rad has been arrested and held after accusing the country's security forces of arresting injured protesters inside hospitals and removing medical equipment, "because they deserve to die".

Dr Rahmani-Rad is an internal medicine specialist who was working at the Rasul Akram public hospital in Tehran when he gave Sky News an interview at the end of January. The regime had regained control of the streets after nationwide protests had threatened to sweep Iran's clerical leaders aside.

Dr Rahmani-Rad said he was shocked by the ferocity of this crackdown, adding the security forces had taken "full control" of the country's hospitals. "If they realise that someone who was injured in the protests has gone to a hospital, or even if they had gone before and managed to escape them, they will arrest that person.

By checking security cameras, they track them down, raid the locations, and detain them," he said. Iran crackdown: Doctors share disturbing accounts His colleagues said security personnel had removed patients from ventilators and other life-saving medical equipment inside hospitals.

"They said, 'let them die, they have no rights, they are against the Islamic system, and they deserve to die'." It was a brave thing to speak out. People who criticise the regime in Iran typically request anonymity, but the medic believed the international exposure would help protect him from state forces.

When I contacted Dr Rahmani-Rad the following week, he said he was fine - although he had received a visit from the security forces. However, these threats did not work.

The specialist posted another video on Instagram - on or around 11 February - castigating the regime for inflicting violence on people who could not afford the money required to treat their injuries. "How could you shoot at these poor souls who don't have 200,000 or 500,000 tomans (£0.90 to £2.40) to buy antibiotics.

I don't understand it. I genuinely don't understand it," he said.

It seems these comments were poorly received. His videos have been stripped from Instagram and the page has been shut down.

Read more from Sky News:Bangladesh's historic electionAnalysis: Trump and Israel's tensionsIS detainees moved from Syria to Iraq Dr Rahmani-Rad's friends are unable to contact him. I spoke to Dr Keyvan Yahia, a neuroscientist who teaches at Chemnitz Technical University in Germany.

He said: "I hadn't heard back from him for three days, so I decided to get hold of Yaser through his father. I said, 'Mr Rahmani, I didn't hear back from Yaser and given the circumstances, I must assume that something not very well happened to him.

Do you have any idea?'" "He said, 'yes, on Monday, actually, on Monday, this week, on his arrival at the hospital... he was officially detained and taken into custody'.

And he was taken, according to his father, to some undisclosed location. The family have absolutely no idea where he has gone." Despite official denials by the regime, doctors have been arrested and detained for providing medical treatment to people involved in the protests.

Sky News understands that a fellow internal medicine specialist, Dr Golnaz Naraghi, was arrested two weeks ago. Her whereabouts was initially unknown, but according to a hospital source, she was transferred to a notorious women's prison called Qarchak near Tehran.

We previously reported on the arrest of a surgeon called Alireza Golchini, who was charged with 'waging war against God' - an offence which carries the death penalty. Dr Golchini posted a phone number online for people injured in the demonstrations, and performed surgery on approximately 20 protesters.

We understand that he has been released on bail and the charges have been changed. The surgeon now stands accused of 'the incitement of protest and rebellion', alongside providing medical care.

He faces the prospect of two to five years in jail..