Russian police head to London for Litvinenko investigation

Vladimir Putin is sending a special squad of Russian police to Britain to investigate the killing of former spy Alexander Litvinenko.

Scotland Yard has received a formal letter from the Russian authorities requesting official clearance for the visit and to interview witnesses.

Police sources told The Independent on Sunday that the Kremlin is eager to shift the blame for Mr Litvinenko's murder away from Russia and President Putin and back towards Britain.

"They have made a formal written request to carry out their own probe. They are eager to deflect the focus away from Russia on to Britain and the British authorities," said one source.

Officers from Scotland Yard have already travelled to Russia to carry out their own inquiries after it was established that the former KGB officer died after ingesting huge amounts of polonium-210, a deadly radioactive substance.

The extraordinary events surrounding his death have also now attracted the attentions of Hollywood.

Johnny Depp, star of the Pirates of the Carribbean series of films, is understood to be in discussions about a starring role in a film about Mr Litvinenko's poisoning. Depp's production company is developing a forthcoming book for the screen.