Calling it the “single largest action targeting corruption to date,” the Department of the Treasury’s Office of Foreign Assets Control (OFAC) on Wednesday sanctioned three prominent Bulgarian individuals along with their network of 64 companies for their “extensive roles” in corruption in Bulgaria.

The sanctions target Vassil Kroumov Bojkov, a Bulgarian businessman and oligarch, for bribing government officials on several occasions. OFAC designated 58 entities registered in Bulgaria that are owned or controlled by Bojkov or one of his companies.

Additionally, the sanctions target Delyan Slavchev Peevski, a former member of parliament and media mogul who has “regularly engaged in corruption, using influence peddling and bribes to protect himself from public scrutiny and exert control over key institutions and sectors in Bulgarian society,” OFAC stated.

OFAC also sanctioned Ilko Dimitrov Zhelyazkov, who is described as the “front man” for Peevski. Zhelyazkov is the former deputy chief of the Bulgarian State Agency for Technical Operations and a former Bulgarian State Agency for National Security officer. He was appointed to the National Bureau for Control on Special Intelligence-Gathering Devices.

“Peevski used Zhelyazkov to conduct a bribery scheme involving Bulgarian residency documents for foreign persons, as well as to bribe government officials through various means in exchange for their information and loyalty,” OFAC stated.

In one example, Zhelyazkov offered bribes to senior Bulgarian government officials in exchange for them providing information that he could pass on to Peevski. “In return, Zhelyazkov would see that individuals who accepted his offer were placed in positions of authority and also provided a monthly bribe,” OFAC stated.

The sanctions were authorized under Executive Order 13818, issued by former President Donald Trump in December 2017. The order builds upon and implements the Global Magnitsky Human Rights Accountability Act and targets perpetrators of serious human rights abuse and corruption around the world.

OFAC’s sanctions coincide with actions taken by the U.S. Department of State publicly designating Peevski and Zhelyazkov, among others, under Section 7031(c) of the Department of State, Foreign Operations, and Related Programs Appropriations Act.