Apple removed an opposition strategic voting app from its online marketplace under pressure from Russian authorities, including threats to arrest local staff of the tech giant, a source familiar with the company's decision told AFP on Friday.

Allies of jailed critic Alexei Navalny accused Apple and Google of "censorship" after they said a "Smart Voting" app advising supporters on how to vote out Kremlin allies had been removed from the companies' app stores.

However, the source said Apple employees faced mounting "bullying tactics and threats to arrest" at the start of a three-day parliamentary election in Russia.

Polls opened across Russia after a year that saw a sweeping crackdown on President Vladimir Putin's opponents
Polls opened across Russia after a year that saw a sweeping crackdown on President Vladimir Putin's opponents AFP / Alexander NEMENOV

Apple and Google did not reply to requests seeking comment.

"They caved in to the Kremlin's blackmail," Leonid Volkov, an exiled aide to Navalny, said on Telegram after Moscow accused the US tech companies of election interference and demanded they remove the app.

Polls opened across the vast country on Friday after a year that saw a sweeping crackdown on President Vladimir Putin's opponents, with Russians given the option of voting online.

The election for seats in the lower house State Duma, which runs until Sunday, comes after a year that has seen Navalny jailed, many of his allies arrested and his organisations banned.