A man is campaigning to free his elderly father from an Iranian jail – four years after he was locked up on suspicion of espionage.

Kamal Foroughi, 76, was taken in for questioning without an arrest warrant or explanation in May 2011 and is currently being held in Evin Prison, in Tehran, Iran.

His son, Kamran Foroughi, 40, from Hertsmere, has not seen his father since March 2011 and is increasingly concerned for his father’s health.

He said: “It is heartbreaking. It’s like they are playing with our minds. It’s a cruel game they are playing and we are very worried about his health.

“We have no idea when he could be released and one day we could just get the call saying he is coming home. It’s a horrible situation to be in.”

According to Mr Foroughi, when his father was arrested his stepmother was told that she could visit him.

She tried every week but was not allowed on most occasions and she managed to see her husband only twice before she lef the country in late 2011.

His father was being held without charge for two years until he was charged with espionage in 2013.

He said: “It was an absolute shock to all of us.

“We have not seen a single piece of evidence and the shock was much bigger than what we would ever imagine.

“He was being constantly questioned and they searched through all of his emails and records.

“In October 2013, my father just disappeared off the system for more than six months and that’s when we got really panicked.

“Then out of the blue we got calls every day and it was clear that they are softening what he is allowed to do.

“The last time I spoke to him, I could tell he was really depressed.”

Mr Foroughi approached the Foreign Office in 2013 and made his father’s case clear to the office but there was no contact between the countries.

In 2011 Iranian protestors stormed the British embassy in Tehran and six British diplomats were initially reported as being taken hostage.

In 2013, the two countries considered opening better relations with each other and in August 2015, the Iranian embassy was officially reopened in London.

Despite building better relations, Mr Foroughi’s father was still deemed an Iranian citizen despite having dual-citizenship.

“We knew that my father hadn’t had any proper medical checks and from late 2013 to when we first when public, I was trying to get the British diplomats to raise it and was raising it myself directly with Iranian diplomats,' Mr Foroughi said.

“The Iranian government kept telling us that everyone gets released after their half sentence on the basis of good behaviour but were very naïve and went along with everything they said.

May 2015 was the fourth year he had been in jail and according to Mr Foroughi the Iranian government kept telling him that after every Eid celebration he was more than likely to be released but he still isn’t.

On November 18 this year, the family heard that Mr Foroughi had a medical test after four and a half years – although his son has little confidence he will see the results.

“I am awaiting the results despite not knowing whether they will be even released to me,” Mr Foroughi said.

“It’s incredible that just one month after going public, the Iranian authorities have acted in providing the basic human need.”

MP for Hertsmere Oliver Dowden is also backing Mr Foroughi’s case and other organisations including Amnesty International have also got involved.

Currently there are more than 50,000 signatures on the change.org petition.