Russia's top diplomat warned on Monday against politicizing the death of former Russian agent Alexander Litvinenko as Moscow announced British detectives had officially requested assistance in the case.

Foreign Minister Sergei Lavrov, speaking on a trip to Brussels, said politicization of the case could damage relations between Russia and Britain.

"The sole concern we are talking about today is the need to avoid politicizing that issue," Lavrov was quoted by the Itar-Tass news agency as saying.

He warned against officials' involvement in fueling the row over Litvinenko's death. "This certainly harms our relations," he said.

Commenting on reports that Russia protested against the publication of Litvinenko's deathbed letter by British media, Lavrov said, "Our diplomats did not and could not have received such instructions," the Interfax news agency reported.

Litvinenko, who was a strong critic of Russian President Vladimir Putin, accused the Kremlin of orchestrating his poisoning in the letter. Moscow vehemently denies the accusation.

Earlier on Monday, the Russian Prosecutor General's Office said in a statement that it had received an official request from Scotland Yard for assistance in collecting information essential to the investigation being conducted in Britain.

A group of Scotland Yard officers arrived in Moscow Monday night to speak to several people who met Litvinenko around the time of his alleged poisoning in early November, news agencies reported.

Litvinenko died of radioactive poisoning late last month in London. Experts investigating his death have found radiation traces at 12 locations and on two British Airways planes that flew the Moscow-London route.

An Italian security consultant who met Litvinenko the day he fell ill has tested positive for traces of the same radioactive isotope believed to have killed Litvinenko.

Litvinenko, who had been arrested several times, fled to Britain with his wife and son in November 2000 and was granted asylum. He became a British citizen last month.

Source: Xinhua