Pavel Lerner, managing director of the Exmo crypto exchange, has been kidnapped in Ukraine, Russia Today reported.
He was reportedly stopped and dragged into a black Mercedes-Benz by men wearing balaclavas while leaving his office in Kiev's Obolon district on 26 December.
The matter is currently under investigation, and that more information will be made public later on, a police spokesman in Kiev told the BBC.
Lerner, 40, is a prominent Russian blockchain expert and has a number of startups in Ukraine linked to cryptocurrency mining and blockchain technology. He is also a managing director of a major UK-based cryptocurrency exchange Exmo.
Exmo Finance is registered with Companies House in the UK, but has its main operations in Ukraine. It has 94,955 active users trading cryptocurrencies.
Separately, Exmo said in a tweet that it been the target of a cyber attack on Thursday.