Russian election officials on Wednesday accused protest leader Alexei Navalny of using dirty tactics in his bid for Moscow mayor after police raided an apartment used by supporters and seized campaign materials.
Navalny is standing as an independent candidate in the September 8 Moscow mayor election, a poll he wants to use as a springboard to fight a nationwide campaign against President Vladimir Putin.
Police said Wednesday that they raided a Moscow apartment after being tipped off that it contained illegal campaign materials in support of Navalny, and detained four people who were charged with resisting police.
Navalny was allowed to run for mayor in a surprise move after a court sentenced him to five years in prison last month for embezzlement in a disputed verdict. But he is facing intense scrutiny from the authorities.
The Rossiya 24 state television channel said a rival candidate for mayor, Nikolai Levychev of A Just Russia party, tipped off the police.
The channel showed police carrying out an activist by his arms and legs after cutting open the door with a chainsaw.
The apartment contained stickers and posters backing Navalny, Rossiya 24 reported, showing some with his official slogans on and some with different wording.
An electoral official told the RIA Novosti news agency that police confiscated around two tonnes of printed materials, though it was unclear how this could have been stored in an apartment.
Navalny's campaign team said in a statement that those detained were from a group of supporters called Brothers of Navalny that was "acting fully independently" from the official campaign.
His team accused police of beating those detained.
Activist Roman Pereverzev wrote on Twitter that he and another detained activist were fined 1,000 rubles ($30, 23 euros) after being detained.
The raid appeared aimed at discrediting Navalny by implying shadowy activities by his campaign team, but it was unclear what effect it could have on his campaign.
Leonid Volkov, Navalny's spokesman, told Slon.ru that he could be expelled from the mayoral race if a court ruled that the illegal materials amounted to more than five percent of the total campaign literature printed, and were made on the orders of his campaign team.
The Moscow electoral commission on Wednesday accused Navalny of using corrupt practices and said that it would take "necessary measures" depending on the result of an investigation by law enforcement authorities.
"It's disappointing that a candidate who positions himself as a 'fighter against corruption' himself uses 'dirty' technologies and shadowy schemes for his election campaign," Moscow electoral commission chief Valentin Gorbunov said in a statement on its website.
According to law, candidates have to put information on all their campaign materials about who produced them and with what print run.
Navalny's team said in a statement that all their campaign materials were "in strict accordance with electoral law".
Earlier this week prosecutors accused him of receiving illegal foreign funding via an online payment system.
The opposition leader's campaign fund is worth just under $1 million (755,000 euros), while the acting mayor Sergei Sobyanin has a fund worth more than $3 million.
In a fiercely fought campaign, Navalny has questioned how Sobyanin's schoolgirl daughter came to own a luxury apartment in Moscow, while the acting mayor's team insisted this was legitimate.
Sobyanin told Business FM radio on Wednesday that his rivals were "trying to use everything they can in this campaign, like in a village brawl."
The VTsIOM state polling agency on Wednesday released a projection showing Navalny coming in second with 13 percent of the vote, which it said Sobyanin would win in the first round with 67 percent.