MOSCOW -- A key witness in the poisoning death of a former Russian security agent was questioned yesterday by British investigators at the Moscow hospital where he was undergoing tests for radiation contamination.
The witness, Andrei Lugovoi, a former security agent turned businessman, met with Alexander Litvinenko at a London hotel on Nov. 1, the day Litvinenko was believed poisoned with the radioactive isotope polonium-210.
Another former officer who took part in the meeting, Dmitry Kovtun, has been diagnosed with radiation poisoning and is believed to be at the same hospital, which once treated victims of the Chernobyl nuclear disaster.
Traces of polonium-210 have been found in Hamburg, which Kovtun visited ahead of the meeting, but it remained unknown whether he was involved in the poisoning or a victim of it.
Lugovoi told the ITAR-Tass and Interfax news agencies that his questioning by British and Russian investigators lasted three hours.
"I gave testimony exclusively as a witness. I was officially informed of that before the interrogation," ITAR-Tass quoted him as saying. "They made no charges against me."
Lugovoi said the results of his medical tests would be known later this week but added he was unlikely to make them public.
Lugovoi told the RIA Novosti news agency that Kovtun, who was interviewed by British and Russian investigators last week, was "feeling normal."
Traces of polonium-210 have now been confirmed in a Hamburg apartment of Kovtun's former wife, where he spent two nights, and the car that picked him up from the Hamburg airport when he arrived from Moscow.
Yesterday, police said that the former wife, her partner, and two small children showed no signs of external contamination but would undergo further tests. They might have been contaminated, for instance, by eating with the same cutlery or drinking from the same glass.
German prosecutors are investigating Kovtun on suspicion that he may have illegally handled radioactive material.
Lugovoi, Kovtun, and a third associate who was in London with them on the weekend of Nov. 1, Vyacheslav Sokolenko, have denied involvement in Litvinenko's death.
Litvinenko -- a former Russian agent who was a fierce Kremlin critic -- died Nov. 23 of poisoning from polonium-210 after blaming Russia's president, Vladimir Putin, also a former intelligence officer, for the poisoning.
Deputy Kremlin spokesman Dmitry Peskov told the BBC's "Newsnight" program that it was "unthinkable that the Russian government can be behind any killing."