Akbari's family received "one last visit" with him on Wednesday before he was placed in isolation.

Akbari, who was Iran's deputy defense minister, was arrested in 2019 and convicted of spying for Britain, which he denies.

Was asked to cancel

Britain called on the Iranian regime to suspend the execution.

Foreign Secretary James Cleverly wrote on Twitter: "This is a politically motivated act by a barbaric regime with complete disregard for human life."

On Saturday, British Prime Minister Rishi Sunak also wrote on Twitter that he was "appalled that the British-Iranian citizen Alireza Akbari has been executed."

He describes the act as cowardly and shows a regime that lacks respect for human rights.

This week, the dictatorship posted a video of Akbari in which he appears to be forced to confess to crimes.

According to audio recordings obtained by the BBC, he has previously said that he was tortured into confessing to crimes he did not commit.