Sky News takes a look at the details of Mr Akbari’s life and the accusations made against him.
Government minister under reformist president
Mr Akbari served as Iran’s deputy defence minister when Ali Shamkhani was minister from 1997 to 2005 as part of reformist president Mohammad Khatami’s administration.
He was a close ally of Mr Shamkhani, who is currently the secretary of Iran’s Supreme National Security Council, since the Iran-Iraq war in the 1980s.
He also served in other security roles, including as an adviser to the Iranian navy, and led the implementation of UN resolution 598, which ended the Iran-Iraq war in 1988.
Mr Akbari had more recently run a private think tank.
Advertisement
Life in Britain and his arrest
Mr Akbari moved to Britain after being briefly detained and released on bail in 2008, according to Iran’s state news agency IRNA.
He was arrested in 2019 and accused of espionage for MI6 concerning past nuclear talks between Iran and western nations, reports said.
Iran’s semi-official Tasnim news agency claimed Iranian intelligence unmasked him by feeding him false information and described him as “one of the most important infiltrators of the country’s sensitive and strategic centres”.
Iranian state media said a video broadcast on Thursday showed Mr Akbari played a key role in the assassination of Iran’s top nuclear scientist in 2020.
Mohsen Fakhrizadeh was killed in an attack, which authorities blamed on Israel.
In the video, Mr Akbari did not confess to being involved in the assassination, but said a British agent had asked for information about Mr Fakhrizadeh.
Iran’s judiciary claimed Mr Akbari received large sums of money, as well as his British citizenship and other help from London, for providing information to MI6.
Please use Chrome browser for a more accessible video player
0:46
‘Drugged and tortured’: Alleged spy told of ordeal
Torture and false confessions
Mr Akbari denied the charge and claimed he was tortured and given mind-altering drugs and forced to confess to crimes he did not commit.
In an audio recording purportedly made by Mr Akbari and broadcast by BBC Persian, he said he had returned to Tehran following an invitation by a senior Iranian diplomat involved in Tehran’s nuclear talks with world powers.
His wife, Maryam Samadi, told BBC Persian he had been put in solitary confinement for 10 months before being moved to Tehran’s notorious Evin prison, where Iran has jailed other dual nationals.
In the recording, Mr Akbari said he had falsely confessed as a result of torture:
He said: “With more than 3,500 hours of torture, psychedelic drugs, and physiological and psychological pressure methods, they took away my will.
“They drove me to the brink of madness… and forced me to make false confessions by force of arms and death threats.
“They would tell me: ‘If you resist, we will send you to the dark cells of Evin prison where you’ll face an interrogator with a whip.'”
In the message, he also said he was accused of obtaining top-secret information from his former boss, Mr Shamkhani, “in exchange for a bottle of perfume and a shirt”. Mr Shamkhani remains in his role.
‘This will not stand unchallenged’
Prime Minister Rishi Sunak has said he was “appalled” by the execution, adding: “This was a callous and cowardly act, carried out by a barbaric regime with no respect for the human rights of their own people. My thoughts are with Alireza’s friends and family.”
Foreign Secretary James Cleverly said: “Iran has executed a British national.
“This barbaric act deserves condemnation in the strongest possible terms.