Facebook has complied with Russian demands to delete some banned content, but it could still face a hefty fine as it was slow to do so, the Vedomosti newspaper cited state communications regulator Roskomnadzor as saying on Monday.
Russia has increased pressure on foreign tech firms in recent months as part of a long-running push to assert greater sovereignty over its segment of the internet.
Roskomnadzor threatened Facebook last week with a fine of up to 10 percent of its annual Russian turnover unless it deleted content that Moscow deems illegal.
Why did Facebook take so long to comply?
Facebook confirmed in a statement on Monday that it deleted content from some of the accounts and pages that were at the heart of a diplomatic row between Moscow and the West.
Russia has accused Facebook and Twitter, and Google's YouTube, of failing to comply with Russian laws, accusing the companies of violating the rights of Russian users.
Facebook said on Sunday that it had agreed to create a dedicated office in Russia to handle requests from Russian authorities. It said it was creating a “transparency center” to display details of government requests for account data.
What content was deleted and why?
Russia has blocked access to Facebook and Twitter over what it said was "hate speech". But Vedomosti said on Monday that Roskomnadzor had not accepted Facebook's argument that the removal of certain posts violated the terms of the companies' operating in Russia.
Roskomnadzor told Vedomosti the company has agreed to delete illegal content, but said that the process had taken too long.
"We warned Facebook, if you fail to do it at a certain level, we will start the process of imposing a warning notice on your company's Russian subsidiary, and a fine of up to 10 percent of the company's sales in Russia will follow," Roskomnadzor head Alexander Zharov was quoted as saying by Vedomosti.
Other points of contention between Russia and Facebook
The newspaper quoted Roskomnadzor’s head Alexander Zharov as saying in an interview that Facebook was deleting or disabling some of the outlawed pages but was still refusing to comply with orders to delete all banned content.
Facebook could face another fine of up to 50,000 roubles ($890.57) for each day the firm failed to comply, Vedomosti said.
Zharov said he expected Facebook to comply with the laws, which only apply to registered Russian companies, and also said Russia could block Facebook if it continued to refuse to do so.
Facebook could not immediately be reached for comment.
In August, Russian lawmakers voted to impose tougher rules on online bloggers and websites, including requiring them to keep local servers.
What does this mean for other tech firms in Russia?
Facebook said it had removed some of the posts the regulator said violated Russian law.
The social media company said it believed it was complying with Russian law in relation to most of the material. It has not said when or how many posts in total had been removed.
Reuters reported last month that Moscow has accused Facebook of failing to remove illegal content from its site, a charge that would put it at risk of a fine of up to 500,000 roubles ($7,900) per post.
Vedomosti reported that Russia's communication regulator did not accuse Facebook of any wrongdoing but said the company could still be penalised.
Facebook is the country's most popular social media platform by users, according to official data.