Russian authorities arrested Ruslan Stoyanov, one of Kaspersky Lab's top-ranked security researchers, under article 275 of the Russian criminal code, which refers to treason.

According to Russian newspaper Kommersant, who broke the story today, Stoyanov was arrested in December, together with the head of the Russian Secret Service (FSB) information security department Sergei Mikhailov.

Kaspersky: Employee arrested for period predating work at company

In a statement released today by Kaspersky Lab, the company says that Stoyanov was arrested based on activities he partook in before joining the company.

The case against this employee does not involve Kaspersky Lab. The employee, who is Head of the Computer Incidents Investigation Team, is under investigation for a period predating his employment at Kaspersky Lab. We do not possess details of the investigation. The work of Kaspersky Lab’s Computer Incidents Investigation Team is unaffected by these developments.

Details regarding the investigation are murky, but according to the Russian newspaper who quotes anonymous sources, Stoyanov was involved in facilitating the transfer of funds from foreign companies to Mikhailov's accounts.

According to Stoyanov's LinkedIn account, before serving as Head of the Computer Incidents Investigation Team at Kaspersky, he worked as Deputy Director for a company called Indrik, but also as a Major in the Ministry of Interior's Cyber Crime Unit.

In the past few years, Kaspersky Lab has worked very closely with Russian authorities to track down and help authorities arrest criminals spread across Russia.

The most recent high-profile arrests where Kaspersky collaborated with Russian law enforcement includes the apprehension of over 50 individuals in May 2016, tied to the creation of the Lurk banking trojan and the Angler exploit kit.