The UK on Wednesday demanded that Tehran halt what it called the "politically motivated" execution of a man convicted in Iran of spying for British intelligence.

"Iran must halt the execution of British-Iranian national Alireza Akbari and immediately release him," foreign minister James Cleverly tweeted.

"This is a politically motivated act by a barbaric regime that has total disregard for human life."

Akbari was sentenced to death for "corruption on earth and for harming the country's internal and external security by passing on intelligence," the Islamic republic's judicial news agency Mizan Online reported on Wednesday.

It did not specify Akbari's age, occupation, date of arrest or sentencing, but said the move had been confirmed by the Supreme Court, without mentioning when.

Citing a statement from the intelligence ministry, Mizan said Akbari became a "key spy" for Britain's "Secret Intelligence Service" -- MI6 -- due to "the importance of his position".

On February 2, 2019, the official government newspaper Iran published an interview with Akbari, whom it identified as a "former deputy defence minister in the reformist government" of Mohammad Khatami, who served as Iranian president from 1997 to 2005.

In early December, Iran put to death four people accused of working with Israeli intelligence, Mizan said at the time.

Iran carried out the sentences four days after the Supreme Court upheld the penalty of capital punishment for "their intelligence cooperation with the Zionist regime (Israel) and kidnapping", Mizan Online had said.