British-Iranian dual national Alireza Akbari, who was sentenced to death in Iran, has been executed, Iranian state media says.
Mr Akbari's family had been asked to go to his prison for a "final visit" on Wednesday and his wife said he had been moved to solitary confinement.
The ex-deputy Iranian defence minister was arrested in 2019 and convicted of spying for the UK, which he denied.
The UK had urged Iran to halt the execution and immediately release him.
On Friday, UK Foreign Secretary James Cleverly warned that "Iran must not follow through with their brutal threat of execution".
"This is a politically motivated act by a barbaric regime that has total disregard for human life," Mr Cleverly tweeted on Wednesday.
Iran posted a video of Mr Akbari this week showing what appeared to be forced confessions.
BBC Persian broadcast an audio message on Wednesday from Mr Akbari in which he said he was tortured and forced to confess on camera to crimes he did not commit.
The United States had joined calls for Iran not to execute Mr Akbari - US diplomat Vedant Patel said "his execution would be unconscionable".
Mr Patel said on Friday that "the charges against Alireza Akbari and his sentencing were politically motivated".
Earlier this week, a UK Foreign Office spokesperson told the BBC that it was supporting Mr Akbari's family and had repeatedly raised his case with Iranian authorities.
It had requested urgent consular access, but Iran's government does not recognise dual nationality for Iranians.
Iran has arrested dozens of Iranians with dual nationality or foreign permanent residency in recent years, mostly on spying and national security charges.
British-Iranian citizens Nazanin Zaghari-Ratcliffe and Anoosheh Ashoori were released and allowed to leave Iran last year after the UK settled a longstanding debt owed to Iran.
However, at least two other British-Iranians remain in detention, including Morad Tahbaz, who also holds US citizenship.
