MOSCOW -- In the bloodstained post-Soviet period, feuds over money and power have often been solved by bullets or bombs. But confirmation that Ukrainian opposition leader Viktor Yushchenko was disfigured by dioxin draws attention to suspicious cases in Russia in which poison may have been used to silence political foes and settle business scores.
As Yushchenko's supporters suggest Russian involvement in the attempt to hurt or kill him, critics of the Kremlin say poisoning is a Soviet-era practice that seems to have reappeared since former KGB officer Vladimir Putin became president and put many of his colleagues from the spy agency into positions of power.
''The list is rather long, and since Putin assumed power in Russia, poisoning has been one of the preferred political tools used by the Kremlin," said Pavel Felgenhauer, an independent Russian military affairs analyst.
Yuri Shchekochikhin, a liberal Russian lawmaker and journalist who crusaded against corruption, died in July 2003 after apparently suffering a severe allergic reaction. Colleagues suspect he was poisoned, probably in connection with his reports on a case involving customs officials and allegations that a furniture store evaded millions of dollars in import duties.
Russia's chief prosecutor's office told Shchekochikhin's colleagues at the Novaya Gazeta newspaper and at the Yabloko political party there was no evidence he was poisoned, Yabloko spokeswoman Yevgenia Dilendorf said. But she said a British laboratory that conducted tests for the paper and the party found that there were signs of poison.
''We unequivocally believe that Shchekochikhin was poisoned," said Vyacheslav Izmailov, a reporter and columnist at the paper.
Izmailov said the same was true for Anna Politkovskaya, a Novaya Gazeta journalist and Kremlin critic who fell seriously ill with symptoms of food poisoning after drinking tea on a flight from Moscow to southern Russia during the hostage crisis in Beslan. At least two other journalists accused authorities of trying to stop them from covering the standoff.
Izmailov points a finger at Russian intelligence agencies such as the Federal Security Service, or FSB, the main successor of the KGB.
He and Felgenhauer also said Chechen rebels held in Russian jails have been poisoned.
''Poisoning is not the only method the security services use to remove people who are inconvenient for them, but it's one of them," Izmailov said.
Felgenhauer said Russian security forces showed their propensity for using lethal substances when they pumped a knockout gas into a Moscow theater seized by Chechen rebels in 2002. Most of the 129 deaths of hostages were attributed to the gas.
''These substances were mostly developed during Soviet times, under the auspices of the KGB," Felgenhauer said. ''And the specialists who designed these kinds of poisons and ways of applying them were trained during Soviet times."
The most notorious Soviet-era case of political poisoning allegedly involving the KGB was that of Bulgarian defector Georgi Markov, who died in London in 1978 after a pellet containing ricin was injected into his thigh -- purportedly by a jab with a rigged umbrella.
The alleged cases of poisoning in the former Soviet Union are not limited to Russia. In Belarus, where critics of authoritarian President Alexander Lukashenko have disappeared and are feared dead, the wife of opposition leader Gennady Karpenko has said he was poisoned shortly before his death in 1999.
Associates of Yushchenko speculate that Russian or former KGB agents may have been involved in poisoning the candidate. Yushchenko fell ill in September and has campaigned with his face disfigured by what doctors who treated him in Austria said last week was poisoning by dioxin.
Supporters say Yushchenko's opponents wanted to kill him or sideline him from the race against Prime Minister Viktor Yanukovych, who was backed by outgoing President Leonid Kuchma and the Kremlin, which holds great influence in the former Soviet republic of 48 million people.