A top cybercrime investigator working for Kaspersky Lab, one of the world's leading security and anti-virus companies, has been arrested alongside an official from Russia's Federal Security Service (Federal'naya Sluzhba Bezopasnosti, or FSB) on charges relating to treason, according to information released by Kaspersky on Wednesday (25 January 2017).

The suspect, Ruslan Stoyanov, is an incident response expert at the firm specialising in distributed denial of service (DDoS) cases. According to his LinkedIn profile, he held a key cybersecurity position at Moscow's Ministry of Interior between 2000 and 2006.

The news emerged from Russia-based newspaper Kommersant and was later reported by online state news outlets. Full details are yet to emerge, but it is understood that the pair have been in pre-trail detention since December 2016.

Kaspersky, his employer since 2012, confirmed the arrest but distanced itself from the ongoing probe. "This case is not related to Kaspersky Lab," a spokesperson said in an emailed statement.

"Ruslan Stoyanov 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."

Over the years, Stoyanov has worked with Russian authorities in a number of major investigations into cybercrime. In a blog post from August 2016, he outlined joint efforts to locate and arrest individuals involved in the "Lurk" gang that stole millions of rubles from banks in the region.

The FSB official arrested alongside Stoyanov, called Sergei Mikhailov, was reportedly the deputy chief at the FSB's Information Security Centre. He now stands accused of receiving money from foreign organisations, according to Kommersant.

Russian state news agency, Tass, has reported the arrests were part of the same case. "Detectives are investigating the Information Security Centre's connection to private companies cooperating with the division in the field of cybercrime expert studies," it stated.

Kaspersky Lab was founded in 1997 in Moscow, Russia, and now operates in nearly 200 countries and territories worldwide. It boasts 400 million users, 270,000 corporate clients and claims to have "no political ties to any government". Yet in March 2015, a Bloomberg report caused a splash by claiming the firm had intimate ties to Russia's security services. It alleged high-level managers in the firm were filled by government intelligence experts and said it failed to report intensively on Russian cybercrime.

Andrei Soldatov, an academic focused on studies relating to Russian security services, told the Associated Press the arrest was unprecedented. He said: "It destroys a system that has been 20 years in the making, the system of relations between intelligence agencies and companies like Kaspersky. Intelligence agencies used to ask for Kaspersky's advice, and this is how informal ties were built. This romance is clearly over."