The founder of one of Russia’s largest cybersecurity companies has been arrested on suspicion of state treason and will be held in a notorious prison run by the security services for the next two months, a Moscow court said on Wednesday.

The charges against Ilya Sachkov, founder of Group-IB, are classified and details of them were not immediately clear. State-run news agency Tass cited an anonymous source who said Sachkov denied passing on secret information to foreign intelligence services.

Group-IB, which specializes in preventing cybercrime and ransomware, confirmed that law enforcement raided its officers yesterday but said it did not know the reason for Sachkov’s arrest.