A law enforcement source reported this to Ukrinform.
According to the source, on May 15, the SSU and the ESBU serve suspicions on Firtash and eight top managers of his companies. In the morning, the heads of the oligarch's companies (RGC, Yie enerhiia) and regional gas companies are searched.
Law enforcement officers exposed a scheme whereby Firtash-controlled entities bought fuel from his own company, but in fact received 30% of the volume. The artificial deficit was covered by state gas, while the money ended up in Firtash's pockets.
The agency's sources say that over the past seven years, this scheme has caused UAH 18 billion in losses to the country's budget.
Law enforcement agencies promised to provide official information later.