MOSCOW, February 2 (RIA Novosti) – A British judge allowed Russian investigators to take part in an upcoming inquest into the death of ex-Federal Security Service (FSB) officer Alexander Litvinenko under the interested party status.

Litvinenko, a former FSB officer who turned critic of the Kremlin and moved from Russia to Britain, was poisoned with the toxic radioactive isotope Polonium-210 in London in 2006, shortly was he was granted citizenship, British investigators claim.

According to an official statement signed by High Court Judge Sir Robert Owen, the Investigative Committee has been granted the status of the interested party in the May inquest amid its promise to disclose Russian classified documents said to be relevant to the case. The statement was released on January 31, but surfaced only on Saturday.

The Investigative Committee “is offering disclosure of evidence which I might otherwise not receive,” the judge wrote.

Russian officials applied for the status in December during a pre-inquest review hearing in London. The intention was protested by Litvinenko’s widow, Maria, who said that the Russia’s participation “… may be subsequently shown to be an abuse of the Court’s process.”

British prosecutors have requested the extradition of two Russians – State Duma deputy Andrei Lugovoi and Dmitry Kovtun – over their alleged roles in the killing. The extradition request was denied by Moscow, though it allowed British police to put questions to the men in Moscow.