Apple has rejected accusations from Russia's state competition watchdog that it fixed iPhone prices.
The Federal Anti-Monopoly Service (FAS) said it was investigating "signs of price-setting coordination" among iPhone resellers following a complaint from a member of the public.
Apple told Reuters it did not control its products' pricing.
"Resellers set their own prices for the Apple products they sell in Russia and around the world," it said.
A citizen told the FAS that the iPhone 6s and iPhone 6s Plus, which went on sale in Russia in October 2015, were priced identically across all 16 major Russian retailers.
Five of the retailers have denied the claims.
The FAS said in a press release it suggested the price-setting was coordinated by Apple, leading to obligatory recommended prices.
"As the preliminary investigations showed, since the start of the sales of iPhone 6s and iPhone 6s Plus, the majority of resellers have fixed and maintained for a certain period of time the same prices for them. Besides, the anti-monopoly authority has identified similarities in the resellers' prices for other Apple smartphones," it added.
The service, which reports to the Government of the Russian Federation, has the power to impose fines on companies it deems to be behaving anti-competitively.
Apple could face a fine of between 1 million rubles ($15,400 ; £11,796) and 5 million rubles, lawyer Oleg Kolotilov from law firm Kulkov, Kolotilov & Partners told the Moscow Times.
The FAS has been contacted for comment.
Apple temporarily stopped selling its devices in Russia in December 2014 after the rouble's value became too volatile.
The previous month it had increased the prices of iPhones, iPads and other products by 20% after the weakened currency left its products cheaper in Russia than the rest of Europe.
Last year a US federal appeals court ruled that Apple conspired with publishers to fix the prices of e-books, resulting in the prices of some titles rising from $9.99 to up to $14.99.