"Twitter Inc has been found guilty under Part 2 of Article 13.41 of the Code of the Russian Federation on Administrative Offenses ("Failure to delete information to which access should be limited")", Zulfiya Gurinchuk, the court's spokesperson, said.
Earlier, Google, Facebook and Telegram were also punished for not removing banned content.
According to Roskomnadzor, the Russian media watchdog, any company could be fined up to 4 million rubles (around $54,000) if it fails to limit access to banned content after receiving the watchdog's notification.
In case of repeated offence, fines increase to one-tenth of a company's total annual income.
In March, Roskomnadzor slowed down the speed of Twitter in Russia for all mobile devices and half of the stationary devices, threatening to completely block it if the company does not follow the requirements of Russian law. The body demanded that over 4,000 prohibited materials be removed, including child pornography, drug- and suicide-related content.
After that, in early April, the court imposed a penalty of 8.9 million rubles on Twitter for refusal to delete posts with calls to minors to participate in illegal actions. However, next month, the Russian media watchdog lauded the social network's efforts to comply with Russian requirements and decided to lift the restrictions partly, keeping slow traffic only on mobile devices.