When Boris Vishnevsky went to check the photo and biographical material that Russia’s election commission planned to post for his candidacy in this weekend’s parliamentary elections, he thought he was seeing double.

Another candidate with the same name was listed alongside him. Then he saw another. They even looked like him, a balding 65-year-old with a stubbly beard.

“On one hand this was very funny because until recently these people had completely different names and they looked different, too,” said Mr. Vishnevsky, an opposition candidate in St. Petersburg. “On the other,” he continued, “they are specifically trying to confuse voters, to deceive them, so that those who want to vote for me vote for one of them by mistake.”