Update at 7am ET: A longer statement from an Exmo spokesperson.

Pavel Lerner, a senior leader for cryptocurrency company Exmo Finance, was kidnapped on Dec. 26 as he left work in Kiev, Ukraine. Russian and Ukrainian media (link in Russian) were the first to report the kidnapping, saying a group of men wearing balaclavas dragged him into a black Mercedes-Benz.

Foreign press were initially unable to verify those particular details, but over the past day the BBC has partly confirmed it: Local police said “a man had been kidnapped on the day in question, but would not confirm his identity.” The police spokesperson told the BBC that more information would be made public later on as the matter was currently under investigation.

Lerner, a globally prominent Russian blockchain expert, is an analyst for Exmo’s exchange, said the company’s spokesperson to Quartz. However, on Lerner’s public-to-view LinkedIn page, he listed himself as the CEO of Exmo Finance. Exmo Finance is registered with Companies House in the UK, with main operations in Ukraine. About 90,000 active users trade cryptocurrencies on its platform.

Following the news, Exmo’s website suffered a distributed-denial-of-service (DDoS) attack on Thursday, where trading was affected temporarily.

An Exmo spokesperson told Quartz:

We are doing everything possible to speed up the search of Pavel Lerner. Any information regarding his whereabouts is very much appreciated. We are kindly asking you to email to bd@exmo.com in case you are aware of any facts that might help the investigation. Despite the situation, the exchange is working as usual. We also want to stress that nature of Pavel’s job at EXMO doesn’t assume access either to storages or any personal data of users. All users funds are absolutely safe.