A British public inquiry said on Thursday that Russian President Vladimir Putin "probably approved" the murder of former spy Alexander Litvinenko. The KGB agent had died in a London hospital in November 2006 after being poisoned with radioactive polonium-210, which was reportedly added to his cup of tea. Litvinenko had acquired British citizenship shortly before his death, after fleeing Russia six years earlier.

The inquiry report represented by far the most damning official link between 43-year-old’s death and the highest levels of the Kremlin, reported PTI. Two Russian men, Andrei Lugovoi and Dmitry Kovtun, have earlier been accused of his murder. The inquiry report said there is a “strong probability” they were acting on behalf of the Russian Federal Security Service, or FSB.

The inquiry found that the "FSB operation to kill Litvinenko" was probably approved by the head of the security service and Putin. Litvinenko’s widow, Marina, welcomed the report’s findings and called for the UK to impose sanctions on Russia, expel all Russian intelligence operatives and impose travel bans on individuals, including Putin.