Iran on Saturday executed former top defence official and dual British national Alireza Akbari, who was accused of spying for UK intelligence, the judiciary reported.
Akbari was executed after being sentenced to death for "corruption on earth and harming the country's internal and external security by passing on intelligence", the judicial news agency Mizan Online reported.
"The actions of the British spy service in this case have shown the value of the convict, the importance of his access and the enemy's trust in him," it added.
Britain had demanded that Tehran halt what foreign minister James Cleverly has called a "politically motivated" execution.
On Thursday, state media had reported that 61-year-old Akbari had held high positions in the country's defence establishment.
His posts included "deputy minister of defence for foreign affairs" and a position in the "secretariat of the Supreme National Security Council".
Akbari had also been an "advisor to the commander of the navy" as well as "heading a division at the defence ministry's research centre".
In a video published by Iranian media, Akbari is seen apparently talking about his contacts with Britain.
He also says he was questioned by the British about Iran's top nuclear scientist Mohsen Fakhrizadeh, assassinated in November 2020 in an attack that Tehran blames on arch-foe Israel.
Akbari, a veteran of the Iran-Iraq war that raged from 1980-1988, was arrested sometime between March 2019 and March 2020, state media said.
Mizan, citing a statement from Iran's intelligence ministry, had said earlier this week that Akbari became a "key spy" for Britain's Secret Intelligence Service, more commonly known as MI6, due to "the importance of his position".
In February 2019, the official government newspaper Iran published an interview with Akbari, whom it identified as a "former deputy defence minister" during the 1997-2005 presidency of Mohammad Khatami.
In early December, Iran executed four people accused of working with Israeli intelligence, Mizan said at the time.
Iran hanged them four days after the Supreme Court upheld their death sentence for "their intelligence cooperation with the Zionist regime (Israel) and kidnapping", Mizan reported.
Akbari's execution comes as Iran has been rocked by protests sparked by the September 16 death of Mahsa Amini, a 22-year-old Kurdish-Iranian, after she was arrested for allegedly wearing her hijab 'improperly'.
Iran's judiciary has confirmed that 18 people have been sentenced to death in connection with the protests, according to a count compiled by AFP from official announcements.
Of these, four have been executed, sparking an international outcry.