Ukraine’s state-owned oil and gas company has filed a lawsuit seeking to overturn a deal struck this summer with a U.S. company co-owned by a former campaign donor to then-Energy Secretary Rick Perry, Time magazine reports. In June, the Ukrainian government awarded the rights to develop a massive complex of oil and gas fields in the country to a firm co-owned by Michael Bleyzer, one of Perry’s longtime allies and key financial backers. Naftogaz alleges in the lawsuit, first reported by Time, that the Ukrainian government acted illegally and with bias in July in agreeing to the deal. Bleyzer insists that his company won the rights fairly and without any political influence, and the Department of Energy denied that Perry advocated for the business interests of any individual or company as energy secretary. Perry was part of a trio of U.S. officials—dubbed the “three amigos”—who led American policy in Ukraine. Perry was one of Trump's original Cabinet members, but left his role this month.