2:45pm UK, Saturday January 27, 2007

The Russian businessman named by Sky sources as the chief suspect in the poisoning of former spy Alexander Litvinenko has denied any involvement in his murder.

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Businessman Andrei Lugovoy

Andrei Lugovoy told Sky News that he had co-operated fully with Scotland Yard detectives when they interviewed him in Russia.

The police want to question Mr Lugovoy about Mr Litvinenko's death on November 23. Both men served as officers in the KGB.

The businessmansaid that the suggestion that polonium had been placed in Mr Litvinenko's tea at the Millennium hotel last November was simply rumour from unofficial sources.

"I have no idea who could be behind his death," Mr Lugovoy told Sky's Alex Rossi. "I, of course, have my own suspicions because we did talk sometimes.

"I am ready to discuss them with the Brtiish and Russian police."

Sky sources say police are in a position to issue an arrest warrant in the case but are not optimistic they will ever be able to charge anyone in connection with this investigation.

Mr Lugovoy and a second man are said to have met Mr Litvinenko in a London hotel on November 1.

Mr Litvinenko, a former spy who became a fierce critic of the Kremlin, became ill that day and died of the effects of radiation poisoning three weeks later.

Mr Lugovoy was treated at a Moscow hospital after Mr Litvinenko's death for what some Russian media said was radiation sickness.

Mr Litvinenko, 41, had been investigating the death of Russian journalist Anna Politkovskaya, like him, a fierce critic of the Kremlin.

He wrote a statement before he died in which he accused Russian President Vladimir Putin of having him murdered.