President Volodymyr Zelensky has fired a slew of senior Ukrainian officials amid a growing corruption scandal linked to the procurement of war-time supplies, in the biggest shakeup of his government since Russia’s invasion began.

During his nightly address on Monday evening, Zelensky announced he was banning government officials from traveling abroad on anything but official business, and said he would be making “personnel changes” in the coming days.

The announcement came after the arrest on Sunday of Vasyl Lozynskyy, the acting minister for regional development. The National Anti-Corruption Bureau of Ukraine has accused Lozynskyy of receiving $400,000 in “unlawful benefits” for facilitating contracts, including for power generators — a sensitive issue in a country that is struggling to cope with freezing temperatures and frequent power cuts caused by Russia’s attacks on its infrastructure.

The National Anti-Corruption Bureau also said it was investigating “high-profile media reports” into allegations that Ukraine’s defense ministry was buying military provisions, including food for the troops, at inflated prices.

Lozynsky’s lawyer Oleksandr Tananakin said Lozynsky had been dismissed from his post before being notified of the allegations. “No funds, let alone in the amounts indicated by the [National Anti-Corruption Bureau], were found and seized from Mr. Lozynsky,” he said in a statement posted on Facebook on Monday. Tananakin then accused the bureau of “deliberately using manipulative tactics to inform the public in order to artificially create a representation of Lozynsky’s guilt and form a negative image of him.”

The full extent of Zelensky’s shakeup began to emerge on Tuesday. Zelensky’s deputy chief of staff Kyrylo Tymoshenko announced his resignation on his Telegram account on Tuesday morning after Ukrainian media reported he was using a vehicle meant for humanitarian purposes and evacuations to go on business trips.

/CNN