Investigators here questioned a key witness Monday in the radiation poisoning death of former KGB agent Alexander Litvinenko, as four more possible victims of contamination were hospitalized for tests -- this time in Germany.
The latest potential victims of radioactive polonium-210 were the former wife of Russian businessman Dmitry Kovtun, her boyfriend and her two children, 1 and 3. Kovtun and a second Russian, Andrei Lugovoy, met with Litvinenko in London hours before he fell ill Nov. 1 and have emerged as central figures in the investigation.
German police have followed a trail of polonium Kovtun left in Hamburg in the days before he flew to Britain for his meeting with Litvinenko. Officials say they have discovered traces of polonium-210 in the passenger seat of the BMW that picked up Kovtun when he arrived in Hamburg on Oct. 28; on a couch in his ex-wife's apartment, where he spent the night Oct. 30; in her mother's home; and on a document Kovtun signed at the immigration office to update his residency. On Monday, they said they had found traces of radioactive elements on the clothing of the ex-wife's boyfriend.
Police said Kovtun was under criminal investigation for bringing the radioactive element into the country.
"He appeared to have been in contact with polonium. We are considering him as a suspect," said Hamburg state prosecutor Martin Koehnke. "We have to establish whether he was poisoned himself or carried the polonium into the country."
Koehnke added that there was a "reasonable basis for suspicion that he may not just be a victim, but could also be a perpetrator."
Authorities theorized that Kovtun was exposed while packaging the polonium-210 before his meeting with Litvinenko.
"We assume he had polonium-210 in his body" when he arrived in Germany, said Elmar Lillpopp, an investigator with the German federal police. Kovtun is not believed to have returned to Germany once he left Nov. 1.
Detectives from Scotland Yard arrived in Hamburg on Monday to work with German authorities on the case. German authorities have dubbed their task force in the case "The Third Man," an allusion to the Graham Greene intrigue novel of the same name and a reference to Kovtun's being the third person at the London meeting, which took place at the bar of the Millennium Hotel in London's upscale Mayfair district.
In Moscow, investigators questioned Lugovoy, the other Russian present at the meeting.
"I was questioned by representatives of the Russian prosecutor general's office in the presence of Scotland Yard detectives," Lugovoy told the Russian news agency Interfax. "I gave full answers to all questions asked by the investigators. I am ready to meet with Russian prosecutor's office representatives and Scotland Yard detectives again."
Both Lugovoy and Kovtun are reported to be at a Moscow hospital suffering from the effects of radiation exposure. Kovtun is believed to be the more seriously ill, but there have been conflicting reports about his condition.
Andrei Piontkovsky, director of the Center for Strategic Studies, a Moscow think tank, said that "given all the emerging evidence, it seems quite clear that Kovtun and Lugovoy brought polonium-210 to London."
"Now they are hidden from the world behind the walls of a highly secure medical establishment. Now the fate of these people is being decided in a Kremlin consumed with panic as to what to do next in the face of the growing heap of hard evidence."
In a written statement prepared shortly before his death, Litvinenko blamed Russian President Vladimir V. Putin for his poisoning. The Kremlin has dismissed the allegation and suggested that exiled opponents of Putin were responsible.
In Russia, speculation has grown over possible conspiracies behind Litvinenko's killing. Suspects have included rogue and official elements of the country's security services, government opponents who might have wanted to cast suspicion on Putin, Kremlin supporters who might have wanted to cast suspicion on the opposition, organized crime and almost every possible combination of the above. So far, no evidence has become public that would support or contradict any of those theories.
Stanislav Belkovsky, president of the National Strategy Institute, another Moscow think tank, said that suspicions were growing "that Lugovoy and Kovtun were the key figures in poisoning Litvinenko." But even if evidence showed that one or both were linked to the crime, the question of whom they were working for and why could remain unresolved, he said.
Holley reported from Moscow and Fleishman from Berlin. Times staff writer Sergei L. Loiko in Moscow contributed to this report.