Akbari, 62, passed information to the UK from 2004 for 15 years, including details about Iran’s nuclear program.

A New York Times report claimed that British intelligence officers told Israeli officials during a meeting in Tel Aviv in 2008 that the UK had infiltrated the Iranian regime, allowing it to identify a secret uranium enrichment facility at Fordow, 20 miles from the city of Qom.

The information was made public by former US President Barack Obama at the 2009 G20 Summit in Pittsburgh, who added that Iran was “endangering the global nonproliferation regime.”

An Israeli official at the time said other intelligence agencies were “shocked” at the information MI6 was able to glean from inside Iran about the Fordow site.

Akbari also passed details to MI6 about more than 100 senior Iranian figures, including Mohsen Fakhrizadeh, the so-called “father of the Iranian bomb” assassinated by Israel in 2020.

A deeply religious hard-line former soldier, Akbari was vocal in his support of Iran’s nuclear program, and was chosen to meet UN Security Council ambassadors in 2004 to assuage fears over Tehran’s plans to develop weapons.

It was around that time, the Iranian regime claims, that Akbari became a spy, receiving £2 million ($2.49 million) from MI6 as well as UK visas for his family.

He retired from his work in Iran’s government in 2008, but remained an adviser to the Supreme National Security Council.

He was later detained and questioned for months on suspicion of being a spy, before being released, after which he moved to London with his family and became a UK citizen.

He traveled back to Iran at least three times, being detained during his final trip to Tehran in 2019, again on suspicion of espionage after the Islamic Revolutionary Guard Corps received information linking him to the Fordow revelations from Russian intelligence.

He was held in the notorious Evin Prison, and on Jan. 11 this year was denounced as a “super spy” by the regime.

He made a public confession, broadcast on Iranian TV, which he later claimed was made following prolonged torture.

“I was interrogated and tortured for over 3,500 hours in 10 months. By using the force of a gun and making death threats they made me confess to false and baseless claims,” Akbari said in a video obtained by BBC Persian.

Akbari was hanged on Jan. 14. His execution was condemned by UK Prime Minister Rishi Sunak, who called it a “callous and cowardly act carried out by a barbaric regime.”

Akbari’s family denies he was a British intelligence asset, claiming he was a victim of internal political power struggles in Iran.

One relative told The Telegraph: “He was a good man who was devoted to his family. Brutal regimes do this to good people and unfortunately this was one of those cases.

“I have fond memories of him visiting us pretty much every Iranian new year regardless of his work schedule. He was kind to me when I was growing up. I remember his smiles.

“As I got older he could see that I was not a supporter of the regime but, regardless of that, because we were family members, he was always kind to me.”

Another relative praised the UK government for its efforts to have Akbari released, telling The Telegraph: “I appreciate what the British government did... but they’re dealing with an unsavory regime that has no regard for human life.”