Ukraine sacked two senior cyber defense officials on Monday, a government official said, as prosecutors announced a probe into alleged embezzlement in the government’s cyber security agency.

Yurii Shchyhol, head of the State Service of Special Communications and Information Protection of Ukraine (SSSCIP), and his deputy, Viktor Zhora, were dismissed by the government, senior cabinet official Taras Melnychuk wrote on Telegram.

Melnychuk, the cabinet’s representative to parliament, did not mention the reasons for the dismissals. Neither man nor their lawyers could be reached for comment.

The SSSCIP is responsible for securing government communications and defending the state from cyber attacks.

News of the firings came less than an hour before anti-corruption prosecutors said they were investigating the head and deputy head of the SSSCIP over their alleged roles in a six-person plot to embezzle 62 million UAH ($1.72 million) between 2020 and 2022.

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Authorities suspect the officials of buying software at an inflated price from two companies allegedly under their control in a sale that had been closed to other bidders, Ukraine’s National Anti-Corruption Bureau said.

Prosecutors did not name either official. In a statement on Telegram, the SSSCIP said it was cooperating with investigators and that all agency procurement had been carried out legally.

Ukraine has stepped up efforts to curtail corruption as it pursues membership in the European Union, which has made the fight against graft a key prerequisite for negotiations to begin.

Recent targets for investigation have included a billionaire former patron of President Volodymyr Zelenskyy and the ex-head of Ukraine’s Supreme Court. Both have denied wrongdoing.

In September, Shchyhol told Reuters that Russian spies are using hackers to target computer systems at law enforcement agencies to identify and obtain evidence related to alleged Russian war crimes.