Litvinenko inquiry: Key suspect 'cannot testify'

A suspect in an inquiry into the death of the former Russian agent Alexander Litvinenko has told the BBC he has not obtained permission to give evidence.

Dmitry Kovtun is one of two men British authorities believe poisoned Mr Litvinenko with radioactive polonium at a London hotel in 2006.

He said he had been unable to get permission from Russian authorities to give evidence at the London inquiry.

Mr Kovtun, who denies involvement, was due to appear by videolink from Moscow.

Gordon Corera reports.