KIEV, March 17 – DTEK, the largest private energy holding of Ukraine, has confirmed that as a part of the investigation by the Swiss authorities into the activities of some former Ukrainian officials, the company has presented financial and legal documents of its Swiss subsidiaries to law-enforcement agencies of Switzerland for study.

"As the DTEK company is fully transparent and it operates strictly according to the law, we'll render assistance to the investigators," reads a response of the energy holding on the request of Interfax-Ukraine regarding the publication in Swiss media.