Sixty-year-old Alexander Makarov, the mayor of Tomsk, suffered a heart attack while meeting with law enforcement officials in the city administration building Wednesday night, the mayor's spokeswoman Nina Schastnaya said.
Local prosecutors said Makarov and his relative were suspected of extorting 3 million rubles ($114,300) from citizens by threatening to destroy their real estate and preventing them from rebuilding.
"We have also opened a criminal case against the mayor's relative, Nina Yegorenkova," the prosecutor's aide Galina Zhoga said, adding that the mayor was arrested before his health deteriorated.
The city administration's press service said Makarov was in intensive care in the Tomsk cardiology institute, but that "the crisis has passed."
The press service also dismissed media reports that Makarov was arrested and taken to a pre-trial detention center.
"According to my information, Mayor Alexander Makarov was rushed to the hospital with a heart attack immediately from his office," a spokesman said.
Makarov's lawyer was not available for comment.
Igor Shaturny, first deputy mayor, is replacing the stricken city head, said Makarov's spokeswoman Schastnaya.
Makarov was elected Tomsk mayor in 1996 and has been re-elected three times since.
The case against the Tomsk mayor is the latest in a series of corruption probes against officials in Russian provinces.
The new investigation follows a probe into another Siberian regional leader in Khakassia in July, and the arrests of the mayor of Volgograd in southern Russia in June and the governor and deputy governor of the northern Nenets Autonomous Area on embezzlement charges in May.
Some 600 bribery and embezzlement cases have been opened in Russia since July, when Putin, who has set the fight against corruption as a national priority, ordered the new prosecutor general, Yury Chaika, to draw up an anti-corruption strategy.
First Deputy Prosecutor General Alexander Buksman said in November that annual corruption in Russia had reached $240 billion, a sum almost equal to the federal budget.
