Head of national joint-stock company Naftogaz Ukrainy Andriy Kobolev has denied the accusation of Yulia Tymoshenko that TrailStone, which sells gas to Naftogaz, was allegedly created in the period when the new Ukrainian government started operating.

"In fact, TrailStone was organized in April 2013 by the team that previously worked at leading positions in Deutsche Bank. Riverstone Holdings private investment firm was founded in 2000 with offices in New York, London, Huston and Mexico became investor in TrailStone. Over the period of its operation the firm invested around $30 billion in over 110 companies in North America, Latin America, Europe, Africa and Asia," Kobolev wrote on his Facebook page.

Naftogaz Ukrainy Business Development Director Yuriy Vitrenko said that Tymoshenko's accusation that Naftogaz Ukrainy buys gas from the affiliated company at a price higher than exchange prices is groundless.

"We do not buy and did not buy gas from any company which is affiliated with the top managers of Naftogaz Ukrainy. As for the company mentioned by Tymoshneko we don't buy and did not buy reverse gas at the price higher than the price on exchanges in Europe plus the cost of transportation to Ukraine. In addition, this is one of the cheapest, if not the cheapest, our supplier," he said.

Vitrenko said that authorized agencies of Ukraine checked TrailStone and other companies, as did the U.S. and EU authorities.