Wanted Verkhovna Rada deputy Oleksandr Onyshchenko has accused Ukrainian President Petro Poroshenko of demanding a $200 million kickback from Ukrainian tycoon Rinat Akhmetov for allegedly unfreezing accounts of the oil and gas producer PrJSC Naftogazvydobuvannya, a charge Akhmetov has refuted categorically.

"The president straight away demanded Akhmetov pay a $200 million kickback, and the latter was shocked because he has been trying to build a transparent company that operates according to European standards," Onyshchenko said in an interview with the Kyiv-based Strana.ua news portal.

Onyshchenko claims the talks broke down after Naftogazvydobuvannya's bank accounts had been frozen.

Akhmetov's press service told the Kyiv-based Interfax-Ukraine news agency he had already commented on the charge leveled by the MP.

"Onyshchenko's claim that money was extorted from me in exchange for unfreezing Naftogazvydobuvannya's assets is absolutely untrue," Akhmetov in December 2016 told the Kyiv-based English-language newspaper Kyiv Post.

He added that charges leveled by Ukraine's Prosecutor General's Office (PGO) against Naftogazvydobuvannya leading the arrest of the bank accounts were settled according to established laws and procedures.

"Naftogazvydobuvannya is operating transparently. All controversies are being settled in Ukrainian and international courts," Akhmetov said.

Strana.ua, in turn, published a comment by the energy holding DTEK, which manages the majority stake of Naftogazvydobuvannya. It says the unblocking of the company's accounts was made possible by the courts and public actions of the company, with the support of the business ombudsman and review of the case pursuant to the convention between Ukraine and the Netherlands on protection of investment, as well as in the European Court of Human Rights.

PrJSC Naftogazvydobuvannya, part of DTEK Naftogas, in 2016 increased gas extraction by 25.3% (or 328.8 million cubic meters), compared to 2015, when the company extracted 1.63 billion cubic meters.

DTEK Naftogas is the operating company responsible for the oil and gas side of the DTEK holding company. Naftogazvydobuvannya and Naftogazrozrobka, licensed to search for oil and gas deposits in Poltava and Kharkiv regions are part of DTEK Naftogas.

DTEK is a strategic holding, with three operating companies which manage coal extraction, heat-generation and distribution, as well as alternative energy and natural gas extraction. The company is part of the financial industrial group System Capital Management (SCM), the largest stakeholder of which is Akhmetov. The CEO of DTEK is Maksym Timchenko. SCM employs 118,000 people.