Iran's official IRNA news agency published a video on Thursday which it said showed that British-Iranian national Alireza Akbari, who is sentenced to death for spying, played a role in the 2020 assassination of the country's top nuclear scientist.  Iran sentenced the former deputy defense minister, who holds dual Iranian-British citizenship, to death on charges of spying for Britain, Iranian state media reported on Wednesday.  Britain described the death sentence on Alireza Akbari as politically motivated and called for his immediate release.  Akbari was a close ally of Ali Shamkhani, who is the secretary of Iran’s Supreme National Security Council and served as Defense Minister from 1997 to 2005 when Akbari was his deputy.  "He was one of the most important agents of the British intelligence service in Iran who had access to some very sensitive centers in the country," Iran's Intelligence Ministry said. "Akbari had fully, knowingly provided information to the enemy's spy service."  Prominent Iranian military scientist Mohsen Fakhrizadeh, killed in a 2020 attack outside Tehran, was widely seen by Western intelligence as the mastermind of clandestine Iranian efforts to develop nuclear weapons. Tehran denied that.