Video footage purporting to show electoral violations at disputed mayoral polls in the Caspian port city of Astrakhan has been doctored, a Russian election official said on Friday.
The clips, uploaded to video-sharing website YouTube by losing opposition candidate Oleg Shein, contain traces of "montage," said Leonid Ivlev, the deputy head of Russia's Central Election Commission (CEC).
Shein and his supporters claim widespread fraud at the March 4 elections, which were won by a pro-Kremlin candidate, and are continuing a four-week hunger strike in their bid to force new polls.
The 40-year-old belongs to the leftist A Just Russia party, which came in third place at parliamentary elections in December.
Russia telecommunications firm Rostelecom provided live webcam streaming from polling stations on voting day.
But Ivlev said the footage was "not authentic."
Shein denied the allegations.
"We posted official government footage on the internet. Anybody can go and make up their own mind," he told RIA Novosti.
Astrakhan authorities have refused to hold a referendum of confidence in the newly elected mayor, Mikhail Stolyarov, A Just Russia lawmaker Dmitry Gudkov wrote on his Twitter account.
Shein is due to lodge a formal appeal with a court later on Friday.
Opposition leaders, including popular blogger and anti-corruption campaigner Alexei Navalny, have joined the Astrakhan protesters.
Left Front opposition leader Sergei Udaltsov has led demonstrations outside Astrakhan region’s representative office in Moscow and has also gone on hunger strike "in solidarity" with Shein.
CEC head Vladimir Churov said on Thursday that he would agree to view webcam footage of alleged fraud at polling stations in Astrakhan if Shein calls off his hunger strike.
In a separate development, dozens of Astrakhan bus drivers went on strike on Friday after the city government stripped them of their licenses.