The wife and friends of poisoned former KGB agent Alexander Litvinenko planned to launch a charitable foundation in his name.

Marina Litvinenko, who kept vigil by her husband's side as he lay dying from a lethal dose of radioactive polonium-210, will be joined by Russian oligarch Boris Berezovsky and the her husband's close friend Alex Goldfarb to announce the creation of the Litvinenko Justice Foundation.

Litvinenko, 43, who died at a London hospital in November, was a forceful critic of the Kremlin, and in a deathbed statement accused Russian President Vladimir Putin of being behind his death, allegations the Russian government denies.

Police in London and Moscow have launched parallel investigations but so far no one has been arrested.

Berezovsky said the foundation would be aimed at aiding investigations into the spy's death, preventing "the same terror attack" in the future, and helping compensate anyone who had suffered psychological, physical or material harm in the case.

Police investigating the case found numerous sites around London contaminated by polonium-210, while several people also tested positive for various degrees of exposure to it.

London police travelled to Moscow last December to conduct inquiries, and last week officials from Moscow spoke to witnesses in London.

Self-exiled tycoon Berezovsky said he and another of Litvinenko's friends, exiled Chechen rebel envoy Akhmed Zakayev, met the investigators in the hope of speeding up the British inquiry.

Scotland Yard has already a file of evidence on the Litvinenko case to Britain's Crown Prosecution Service, which will decide if any charges are to be brought.