The wife and friends of former Russian security agentAlexander Litvinenko began a campaign Tuesday to pressure investigators to findthose responsible for his poisoning death more than four months ago.

Marina Litvinenko was joined by Russian tycoon Boris Berezovsky and herhusband's close friend, Alex Goldfarb, to announce the creation of theLitvinenko Justice Foundation.

"We will campaign to make sure that governments take all possible stepsto ensure that this crime is never repeated," she said in a statement.

Alexander Litvinenko, 43, died at a Londonhospital Nov. 23. from a lethal dose of radioactive polonium-210. In a deathbedstatement, he accused Russian President Vladimir Putinof being behind his death, allegations the Russian government has denied.

Police in London and Moscow have launched parallel investigations,but no one has been arrested. Scotland Yard has sent a file of evidence in thecase to Britain'sCrown Prosecution Service, which will decide if any charges will be brought.

Litvinenko, who claimed publicly in 1998 that his bosses in the FederalSecurity Service had ordered him to kill Berezovsky, fled to England in2000. Berezovsky was an influential Kremlin insider, but fell out with Putinand also left for England.The two men became allies in their campaigns against the Kremlin leadership.

Berezovsky said the foundation would push for progress in the investigationsand help compensate anyone who suffered psychological, physical or materialharm in the case. Police investigating the case found several sites around London contaminated bypolonium-210. Several people tested positive for contamination.

"Until the method of this absolutely new type of killing using anuclear micro-bomb is uncovered, not a single person in the U.K. orelsewhere in the world can feel safe against a similar murder," Berezovskysaid.

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

Berezovsky said he and another of Alexander Litvinenko's friends, exiledChechen envoy Akhmed Zakayev, met the investigators in the hope of speeding upthe British inquiry.