Iranian state media published a video on Thursday which they said showed that British-Iranian national Alireza Akbari, who is in detention and sentenced to death for spying, played a role in the 2020 assassination of the country's top nuclear scientist.
In the video, Akbari did not confess to involvement in the assassination of scientist Mohsen Fakhrizadeh, killed in a 2020 attack outside Tehran, but said a British agent had asked for information about him.
In a separate audio recording broadcast by BBC Persian on Wednesday, Akbari, a former Iranian deputy defense minister, said he had confessed to crimes he had not committed during months of torture in detention.
In the video, Akbari did not say what, if any, information he shared or with whom.
"They wanted to know about high-ranking officials depending on the major developments ... for example he (the British agent) asked me whether Fakhrizadeh could be involved in such and such projects and I said why not," Akbari, said in the video broadcast by Iran's state news agency IRNA, one of several clips broadcast on Thursday.
The authenticity of the video and audio or when or where they were recorded could not be immediately established.
Iranian state media reported on Wednesday that Iran had sentenced Akbari to death on charges of spying for Britain. Akbari holds dual Iranian-British citizenship.
Britain's foreign office declined to comment on the videos.
On Wednesday, British foreign minister James Cleverly said the planned execution was politically motivated and called for his immediate release. The foreign office also said on Wednesday its priority was securing his immediate release.
Ties between London and Tehran have deteriorated in recent months as efforts have stalled to revive Iran's 2015 nuclear pact, to which Britain is one of the parties.
Britain has also been critical of the Islamic Republic's violent crackdown on anti-government protests sparked by the death in custody of a young Iranian-Kurdish woman in September
Fakhrizadeh was widely seen by Western intelligence as the mastermind of clandestine Iranian efforts to develop nuclear weapons. Tehran denied that.
Iran’s state media often airs purported confessions by suspects in politically charged cases.
Akbari was sentenced on charges of "corruption on earth and extensive action against Iran’s internal and external security through the transmission of information to Britain", the judiciary's Mizan news agency said.
It said his appeal had been rejected by the supreme court.
In the audio recording broadcast by BBC Persian, Akbari said he was extensively tortured in custody.
"I was interrogated and tortured for over 3,500 hours in 10 months. All of that were recorded on camera ...By using the force of gun and making death threats they made me confess to false and baseless claims," Akbari said in the audio message.
Akbari was a close ally of Ali Shamkhani, secretary of Iran’s Supreme National Security Council who served as defense minister from 1997 to 2005 when Akbari was his deputy.
"I was accused of obtaining top secret information from Shamkhani in exchange for a bottle of perfume and a shirt during (former President Hassan) Rouhani's presidency," Akbari said in the audio message.
In another video, aired by Iran's state news agency IRNA, a caption read "Akbari moved to Britain after being briefly detained and released on bail in 2008". Another video showed Akbari blindfolded in a car.
It could not be immediately verified if Akbari had moved to Britain in 2008, or when he returned to Iran.
In his audio message, Akbari said he had returned to Tehran following an invitation by a senior Iranian diplomat involved in Tehran's nuclear talks with world powers.