But Tatyana Chernyshova, a spokeswoman for the Prosecutor-General's Office, said petitions with false signatures were discovered in Rybinsk, in Yaroslavl Oblast, north of Moscow.
She said that members of Kasyanov's campaign staff "falsified signature lists containing more than 3,500 citizens' signatures. Since these actions bear the hallmarks of a crime..., the evidence about the uncovered violations has been sent to the department of investigations in Rybinsk of the [Federal] Investigative Committee...for the opening of a criminal case."
Chernyshova added that an additional 12,000 falsified signatures were discovered in the Mari El Republic, where a criminal case has also been launched.
'He Has Fulfilled His Role'
Yevgeny Volk, a political analyst with the Heritage Foundation in Moscow, says the Kremlin wants to ensure that its anointed candidate, First Deputy Prime Minister Dmitry Medvedev, wins handily in the election's first round. Volk says that although Kasyanov is a weak candidate, he could potentially siphon critical votes away from Medvedev.
"In think the task right now is to remove him from the presidential race, or to discredit him," Volk says. "I think he will have a lot of difficulty registering."
On January 11, security officials detained six Kasyanov campaign workers in Mari El and tried to get them to admit to illegal campaign activities.
Speaking to RFE/RL's Russian Service on January 22, Kasyanov said that "of course, we understood that our activity was unpleasant to the authorities because we speak the truth and the truth, of course, always reaches the people. That is why we have no access to the mass media."
Volk and other analysts have long alleged that the only reason the Kremlin even allowed Kasyanov's candidacy to get this far was to divide the liberal opposition and prevent the emergence of a single strong candidate. "He has fulfilled his role," Volk says. "There is nobody on the right flank that can compete with him. Kasyanov has played the role of spoiler."
Former world chess champion Garry Kasparov intended to contest the election as a liberal opposition figure. His supporters, however, were not allowed to rent halls for a required nomination gathering. Boris Nemtsov, another opposition figure, announced in December that he would not run.
Putin is constitutionally banned from seeking a third consecutive term. He has endorsed Medvedev, who is widely expected to sail through the election.
Communist Party leader Gennady Zyuganov and Vladimir Zhirinovsky, head of the nationalist Liberal Democratic Party, have also registered to run on March 2. Neither presents a significant challenge to Medvedev.