Litvinenko lawyer accuses UK, Russia of cover-up

Litvinenko, a Russian intelligence agent turned Kremlin critic, died in London in November 2006 after drinking tea laced with the rare radioactive isotope polonium-210.

The allegations of a cover-up came at a London court hearing where British media organizations challenged a government bid to hold parts of the inquest in secret for security reasons. In Britain, inquests are held to determine the facts whenever someone dies violently, unexpectedly or in disputed circumstances.

Ben Emmerson, the lawyer for Litvinenko's widow Marina, said the government's quest for secrecy was delaying proceedings and suggested that foreign policy — namely trade relations — could be at the heart of the matter.

"We know nothing about why these applications are being made and we are dancing in the dark," he told coroner Robert Owen. "This is beginning to look like you're being steamrollered by two states acting in collaboration with each other."

Lawyers for Litvinenko's family say at the time of his death he was working for the British intelligence services, and Britain accuses two Russians of the killing. Moscow authorities have refused to extradite them for trial.

British government lawyer Neil Sheldon said "the disclosure of the material in question would pose a real risk to the public interest."