Ukraine's anti-corruption bodies said on Saturday they had uncovered a major graft scheme that procured military drones and signal jamming systems at inflated prices, two days after the agencies' independence was restored following major protests.

The independence of Ukraine's anti-graft investigators and prosecutors, the National Anti-Corruption Agency (NABU) and the Specialised Anti-Corruption Prosecutor's Office (SAPO), was reinstated by parliament on Thursday after a move to take it away resulted in the country's biggest demonstrations since Russia's invasion in 2022.

In a statement published by both agencies on social media, NABU and SAPO said they had caught a sitting lawmaker, two local officials and an unspecified number of National Guard personnel taking bribes. None of them were identified in the statement.

"The essence of the scheme was to conclude state contracts with supplier companies at deliberately inflated prices," it said, adding that the offenders had received kickbacks of up to 30 percent of a contract's cost.

NABU said it has made four arrests so far but did not identify those detained.

The interior ministry said it had suspended the suspected members of the National Guard.

Zelensky, moving to defuse crisis, restores power of anti-graft agencies

"There can only be zero tolerance for corruption, clear teamwork to expose corruption and, as a result, a just sentence," President Volodymyr Zelensky wrote on Telegram.

Zelensky, who has far-reaching wartime presidential powers and still enjoys broad approval among Ukrainians, was forced into a rare political about-face when his attempt to bring NABU and SAPO under the control of his prosecutor-general sparked the first nationwide protests of the war.

Zelensky subsequently said that he had heard the people's anger, and submitted a bill restoring the agencies' former independence, which was voted through by parliament on Thursday.

Top European officials had told Zelensky that Ukraine was jeopardising its bid for European Union membership by curbing the powers of its anti-graft authorities.

"It is important that anti-corruption institutions operate independently, and the law adopted on Thursday guarantees them every opportunity for a real fight against corruption," Zelensky wrote on Saturday after meeting the heads of the agencies, who briefed him on the latest investigation.

Several cases of corruption – an endemic problem in the country – have been exposed within the armed forces and the defence ministry during the war with Russia.