Ukrainian investigators suspect a lawmaker of trying to bribe the head of a government reconstruction agency in the country’s first-ever documented cryptocurrency kickback, authorities said on Tuesday.

The National Anti-Corruption Bureau of Ukraine (NABU) said the lawmaker, a parliament’s anti-corruption committee member, is believed to have offered the equivalent of $50,000 in bitcoin in exchange for state funds to rebuild infrastructure under his control.

The bureau did not name the official, whom prosecutors served with an official notice of suspicion.

The head of Ukraine’s State Agency for Restoration and Infrastructure Development reported the bribe to authorities after receiving the first $10,000 tranche, NABU said.

“This is the first illegal benefit in cryptocurrency in the history of (Ukraine’s) anti-corruption institutions that has been documented,” the agency said in a statement.

Ukraine has stepped up efforts to stamp out corruption as it pursues membership of the European Union, making the fight against graft a critical condition for negotiations to begin.

In an interview with Reuters earlier this year, NABU chief Semen Kryvonos said his agency would prioritize fighting wartime crimes in strategic sectors like defense and reconstruction.

On Tuesday, investigators announced they suspected two high-ranking cyber security officials of embezzlement.

In a statement on Facebook, the state reconstruction agency said zero tolerance of graft was “a key principle” of its work.

“Our cooperation with law enforcement and anti-corruption agencies was and will be systemic,” it said.