Ukrainian President Volodymyr Zelensky said he has had no contact with his former business partner since a sweeping corruption probe began into alleged kickbacks in the country’s energy sector – a scandal that has already forced two ministers to resign and shaken his administration.

In an interview with Bloomberg on Wednesday, Zelensky vowed to support a full investigation into the case, which targets senior officials and businessmen accused of embezzling millions from defense-related energy contracts.

“The most important thing is sentences for those people who are guilty,” Zelensky said. “The president of a country at war cannot have any friends.”

He confirmed that he has not spoken to Timur Mindich, a co-owner of his former comedy production company Kvartal-95, which produced the president’s hit TV series Servant of the People.

The National Anti-Corruption Bureau of Ukraine (NABU) alleges that Mindich helped organize a $100 million kickback scheme involving contracts at Energoatom, Ukraine’s state nuclear operator.

Zelensky said he had asked the government to impose sanctions on Mindich and businessman Oleksandr Tsukerman, both suspected of involvement in the scheme.

The State Border Guard Service said Mindich fled Ukraine hours before anti-corruption agencies announced the case.

“There is business and there are some government officials that are in this investigation,” Zelensky said.

“First of all, ministers bear political responsibility, and then, depending on investigation and court rulings, other responsibility.”

According to NABU and the Specialized Anti-Corruption Prosecutor’s Office (SAPO), top Energoatom officials allegedly demanded illicit commissions of 10-15 percent from contractors building defenses to protect nuclear energy facilities from Russian attacks.

NABU-released recordings suggest that Justice Minister and former Energy Minister Herman Halushchenko – who resigned Wednesday – may have helped launder money.

Energy Minister Svitlana Hrynchuk also resigned after Zelensky said she “cannot remain in office.” Both have denied wrongdoing and have not been formally charged.

The scandal has sparked public outrage as millions of Ukrainians endure rolling blackouts from intensified Russian strikes on the energy grid.

In his nightly address on Wednesday, Zelensky called corruption in the energy sector “absolutely unacceptable during wartime” and urged officials to step down “to preserve public trust.”

Prime Minister Yulia Svyrydenko confirmed that Energoatom’s vice president and several senior executives were suspended pending the outcome of the probe.

NABU said 5 people were detained during a 15-month investigation into “large-scale” graft. The government has since dissolved Energoatom’s supervisory board.

“As president, I must ensure that anti-corruption agencies have all powers and I don’t influence them,” Zelensky told Bloomberg. “Everyone must be equally accountable before the law.”