Traces of radiation found at two sites in Germany linked to a contact of poisoned former Russian spy Alexander Litvinenko likely are the rare radioactive substance polonium-210, authorities said yesterday.

Police said on Saturday that traces of alpha radiation had been found at properties in and near Hamburg used by the ex-wife and former mother-in-law of Dmitry Kovtun.

The Russian businessman met Litvinenko in London on November 1, the day the former spy is believed to have fallen ill. Litvinenko was killed by polonium-210.

Germany's Federal Office for Radiation Protection said in a statement yesterday that "small traces of radioactive substances were detected, and there is a high degree of probability that this is polonium."

In another development, Russian investigators plan to visit London to conduct inquiries into the killing of Litvinenko, Moscow authorities said, as British police confirmed that two detectives investigating the case had tested positive for traces of radiation.

The Metropolitan Police said yesterday that two officers had tested positive for "relatively small traces" of polonium-210, the radioactive substance used to poison the former KGB spy. It said 24 other officers working on the case had been tested and cleared.

It said the two contaminated officers were in good health and were being monitored by health specialists.

Officials also tested a plane from airline Germanwings that was used by Russian businessman Kovtun, who met Litvinenko in London on the day Litvinenko became ill. Germanwings said no traces of polonium-210 were found on the Airbus A-319 Kovtun took from Hamburg to London on November 1.

At London's Millennium Hotel in Mayfair where Litvinenko drank tea in the Pine Bar on November 1 with Kovtun and a group of fellow Russians, and where he appears to have been poisoned officers were testing a cup and a dishwasher for traces of polonium, Britain's Daily Telegraph said. Officials said they could not immediately comment on the report.

Litvinenko's widow, in her first public comments since his death, said she did not want to help Russian authorities with their investigation.

Marina Litvinenko said she did not believe Putin was personally responsible for the death of her husband, who acquired British citizenship this year.

Source: China Daily