People were instructed to take their ballot, sign for Vladimir Putin, and bring it back to the car to show them and claim a bottle, Karpov said.
And when such methods of persuasion did not work, Putin's supporters resorted to other means, Karpov said.
"In one case the protocols at one polling station did not coincide with our copy. A number of votes for Gennady Zyuganov were missing. When we complained to the territorial elections commission, we were told that a commissioner was sent to the polling station and he found the missing ballots somewhere in a table drawer!" said Karpov. "If we had not insisted, no one would have looked for those ballots or corrected the protocol.
"We started to prepare lawsuits, but we are not qualified enough to do that," said Karpov, adding that in the end no cases were filed.
"Our problem is that we are not legally prepared to prove in court that we are right."
But Karpov was hoping that he might hear better news from Moscow or other regions where allegations of election fraud are plentiful.
"It is sad that we have not heard a single case when the head of a polling station was imprisoned for what he [or she] did," said Karpov.