A British-Iranian man who had previously served as Iran’s deputy defense minister was hanged, according to the country’s judiciary, despite requests from London and Washington for his release after being sentenced to death for espionage against Britain.

The execution was denounced by Britain, which had ruled the case against Alireza Akbari to be politically motivated. Prime Minister Rishi Sunak described it as “a callous and cowardly crime carried out by a barbaric regime.”

Akbari, 61, was arrested in 2019.

The Iranian judiciary’s Mizan news agency reported the execution without saying when it had taken place. Late on Friday, British Foreign Secretary James Cleverly had urged Iran not to follow through with the sentence.

Also condemned by the United States and France, the execution looks set to further worsen Iran’s long-strained relations with the West, which have deteriorated since talks to revive its 2015 nuclear deal hit deadlock and after Tehran unleashed a deadly crackdown on protesters last year.

In an audio recording purportedly from Akbari and broadcast by BBC Persian on Wednesday, he said he had confessed to crimes he had not committed after extensive torture.

“Alireza Akbari, who was sentenced to death on charges of corruption on earth and extensive action against the country’s internal and external security through espionage for the British government’s intelligence service … was executed,” Mizan said.

The Mizan report accused Akbari of receiving payments of 1,805,000 euros ($1.95 million), 265,000 pounds ($323,989.00), and $50,000 for spying.

Cleverly said in a statement the execution would “not stand unchallenged”. He later announced Britain had summoned the Iranian Charge d’Affaires, imposed sanctions on Iran’s prosecutor general, and temporarily withdrawn its ambassador from Tehran for further consultations.

It marks a rare case of the Islamic Republic executing a serving or former senior official. One of the last occasions was in 1984, when Iranian navy commander Bahram Afzali was executed after being accused of spying for the Soviet Union.

British statements on the case have not addressed the Iranian charge that Akbari spied for Britain.

Iran’s foreign ministry summoned the British ambassador over what it called London’s “meddling in Iran’s national security realm”, the state news agency IRNA reported.

Iranian state media, which have portrayed Akbari as a super spy, broadcast a video on Thursday which they said showed he played a role in the 2020 assassination of Iran’s top nuclear scientist, Mohsen Fakhrizadeh, killed in an attack outside Tehran which authorities blamed at the time on Israel.

In the video, Akbari did not confess to involvement in the assassination but said a British agent had asked for information about Fakhrizadeh.

Iran’s state media often airs purported confessions by suspects in politically-charged cases.

Reuters could not establish the authenticity of the state media video and audio, or when or where they were recorded.

Akbari was a close ally of Ali Shamkhani, now the secretary of Iran’s Supreme National Security Council, who was defense minister from 1997 to 2005. Akbari fought during the Iran-Iraq war in the 1980s as a member of the Revolutionary Guards.

Ramin Forghani, a nephew of Akbari, told Reuters the execution had come as a shock.

“I don’t think a person who spent all his life, from an early age, to serve the country – since the Iran-Iraq war – would spy for any country,” he said, noting Akbari had the rank of colonel in the Revolutionary Guards.

Speaking by phone from Luxembourg, he said Akbari’s wife, who lives in London, had tried but failed to persuade Iranian officials to spare his life. Reuters was unable to reach her.