A cybersecurity researcher working for anti-virus firm Kaspersky Lab in Russia has been arrested.
Ruslan Stoyanov, a member of Kasperksy's investigations team, was arrested in December but news of his apprehension has only just surfaced.
He was arrested as part of an investigation into payments he allegedly received from foreign firms.
At Kaspersky, Mr Stoyanov helped look into hack attacks and breaches at Russian companies.
In a statement, Kaspkersy Lab said the arrest had nothing to do with his work for the security firm.
"Ruslan Stoyanov is under investigation for a period predating his employment at Kaspersky Lab," said the company in a statement. Mr Stoyanov joined Kaspersky in 2012.
It added: "We do not possess details of the investigation."
Prior to working for Kaspersky, Mr Stoyanov was employed at other security firms. From 2000 to 2006 he was a major in the Russian Ministry of Interior's Moscow cybercrime unit.
Information about the reasons for the arrest are scant, but one Russian newspaper linked it to a probe into Sergei Mikhailov - a senior official at Russia's FSB intelligence service.
Forbes reported that Mr Stoyanov has been arrested under Article 275 of Russia's criminal code which lets prosecutors charge people for treason for "providing financial, technical, advisory, or other assistance" to other countries or non-Russian organisations seen as hostile.