The inquest into the death of murdered Russian former spy Alexander Litvinenko could examine the possible role of British spies in his death, according to BBC News.

MI6 and the Russian secret service, the FSB, may become "interested parties", a pre-inquest review has heard.

The inquest is set to be held as soon as possible next year.

Mr Litvinenko, 43, is thought to have been poisoned with polonium-210 after meeting two Russians for tea at a central London hotel in November 2006.

The pre-inquest review was held on Friday at Camden Town Hall, in north London.

Hugh Davies, counsel to the inquest, said it could extend to include "the possible culpability of the Russian state", as well as "the possible culpability of the British state in the death of Alexander Litvinenko either: one, in carrying out by itself or its agents the poisoning; or two, failing to take reasonable steps to protect Mr Litvinenko from a real and immediate risk to his life".

He said the Russian state has been invited since January to become an interested party in the inquest, although the offer had not yet been taken up.

The BBC's Gordon Corera said interested party status would mean its representatives would be able to cross-examine witnesses and examine documents.

Mr Davies told the hearing there were a "number of competing and increasingly controversial theories" surrounding Mr Litvinenko's death.

He said the inquest's scope could include involvement of other parties, including his friend, a fugitive Russian tycoon Boris Berezovsky, Chechen-related groups and the Spanish mafia.