British police have officially requested assistance from their Russian counterparts while investigating the poisoning death of a former KGB agent, and a group of police officers arrived in Moscow Monday to collect information.

Meanwhile, lawyers for another former security officer, Mikhail Trepashkin, jailed in central Russia, appealed to the British officers to collect testimony as soon as possible. They said he possessed key evidence in the case, but that his life was threatened.

Alexander Litvinenko, 43, died on November 23 in London after ingesting radioactive polonium-210. In a deathbed accusation, he cursed Russian President Vladimir Putin for the poisoning, accusations the Kremlin has vehemently denied.  

In a letter from prison, Trepashkin, who is serving a four-year sentence for revealing state secrets, wrote he had warned Litvinenko several years ago about a government-sponsored death squad that were targeting him and other Kremlin opponents.

His supporters demanded Monday that Trepashkin be allowed to testify to the British police officers, saying he was not receiving adequate treatment for asthma in prison. "His life is in danger and he may die any night of asthma," said his lawyer Yelena Liptser.

Russian Foreign Minister Sergey Lavrov warned Monday that continued suggestions of Russian official involvement in Litvinenko's death could damage relations with Britain.

Lavrov said he had spoken with British Foreign Secretary Margaret Beckett "about the necessity to avoid any kind of politicization of this matter, this tragedy," the RIA-Novosti news agency reported.

"If the British have questions, then they should be sent via the law enforcement agencies between which there are contacts," he said.

Russia's Prosecutor-General's office released a statement agreeing to help Scotland Yard officers in the investigation. A Foreign Ministry spokesman said Russia has issued visas for the team.

British Home Secretary John Reid, speaking during a trip to Brussels Monday, said police had left for Moscow. This was confirmed when British law enforcement authorities revealed a team of nine officers were to travel to Moscow.

(China Daily December 5, 2006)