Mikhail Grishankov, a deputy of the State Duma and former Federal Security Service officer, joined Russia Today to analyse the statement of Andrey Lugovoy on the Litvinenko case.

Russia Today: Russia's Federal Security Service has said it will investigate the allegations made by Andrey Lugovoy. What makes the FSB get involved in the case?

Mikhail Grishankov: The FSB checks out any kind of information of possible threat to Russia's security. Lugovoy stated that Beresovsky and Litvinenko per se exchanged the information, which Berezovsky possessed when he was Deputy Secretary of the Security Council, for political asylum in London. That is why the damage caused by their passing of this information must be estimated.

RT: Some media reports are suggesting that the fact Lugovoy came out yesterday and made such a strong allegation against Britain's MI6 is proof that he has Kremlin backing. Others are suggesting that the allegation he levied is just a 'smokescreen' in order to distance himself from what should be treated as a criminal matter. What do you say to that?

M.G.: It is only natural that Lugovoy, protecting himself from the British allegation, would start to share a lot of information which would definitely be far from being pleasant for Russia, I mean selling secret information to foreign intelligence, and also, I think, for certain British politicians, because the way, as stated by Lugovoy, of how British citizenship can be bought is really an unpleasant revelation for many Britons. Besides, I suppose that Lugovoy is not exactly happy talking about his contacts with Berezovsky, and not just because Berezovsky has an established image in Russia. In fact, his deeds over the last years have nothing to do with common sense. I would like to stress the fact that it is true that all those who contact with Berezovsky come to an unpleasant end. They are all kinds of people: journalist Listyev, deputy of the State Duma Golavlev and another deputy of the State Duma Yushenkov and unfortunately the assassinated journalist Anna Politkovskaya.  There are too many odd coincidences happening to people communicating with Berezovsky. Surely the information provided by Mr Lugovoy must be thoroughly examined. I believe that both Russian and British law-enforcement agencies must take part in this examination.

RT: And in terms of investigation. Lugovoy has presented his three versions of who or what is behind the murder of Litvinenko and that are MI6, Boris Berezovsky and all the Russian mafia. Which of those three in your opinion is the most credible?

M.G.: You know, the simplest version is the one presented by British Royal Prosecution. They said Lugovoy and Litvinenko drank tea together and one poisoned another. Just think it over. I believe detective-lovers must have analysed these statements quite seriously. So just imagine the man who chooses to kill somebody by drinking tea with him and poisoning him is like leaving your passport in the crime scene. Doubtlessly Lugovoy knows that any radioactive material can be easily identified and traced. If he were plotting anything against Litvinenko he would consider that. Therefore accusation of Lugovoy is, to put it mildly, unfounded.

As for Berezovsky and Russian mafia versions – they are possible. They both are possible, it is just necessary to check out thoroughly everything Litvinenko did. Trying to make his living in London, he surely did all kind of things, which means crossing somebody's interests as well. And if Lugovoy's information about Litvinenko bargaining with Berezovsky over compromising evidence on the latter is true, than it is definite that Mr Berezovsky had reasons to take care of Litvinenko in a certain way. There is plenty of work for Scotland Yard, British Royal Prosecution and surely for the Russian Prosecutor General's Office to be done. The must check out in detail everything Mr Lugovoy has said.