A manager at Russia’s biggest cybersecurity firm in charge of investigating hacking attacks has been arrested, the company has said.

Kaspersky Lab on Wednesday confirmed reports in Russia’s respected Kommersant newspaper that Ruslan Stoyanov, the head of its computer incidents investigations unit, was arrested in December. Kommersant said Stoyanov was detained along with a senior Russian FSB intelligence officer and that they both faced charges of treason.

Kaspersky’s spokeswoman, Maria Shirokova, said in a statement that Stoyanov’s arrest “has nothing to do with Kaspersky Lab and its operations”. She said the company had no details of the charges Stoyanov faced, but added that the investigation dated back to the time before Stoyanov was hired by Kaspersky.

According to his LinkedIn page, Stoyanov’s previous jobs include a position at the cybercrime unit at the Russian interior ministry in the early 2000s.

US intelligence agencies have accused Russia of meddling in the presidential election through hacking to help Donald Trump win – claims that Russia has rejected. US and EU officials have also accused Russia of hacking other western institutions and voiced concern that Russia may try to influence this year’s elections in Germany, France and the Netherlands. It was not immediately clear if the arrests were linked to these allegations.

The FSB’s press office was not immediately available for comment. Kremlin spokesman Dmitry Peskov also declined to comment.

Andrei Soldatov, who has studied the internet and Russian security services for more than a decade, said the arrest of the Kaspersky manager was unprecedented.

“It destroys a system that has been 20 years in the making, the system of relations between intelligence agencies and companies like Kaspersky,” he told the Associated Press. “Intelligence agencies used to ask for Kaspersky’s advice, and this is how informal ties were built. This romance is clearly over.”