Dozens of battered trucks laden with gold-bearing ore snake their way across the desert in northeastern Sudan and dump their loads at a compound on the outskirts of the town of Atbara.

The tons of ore, extracted by small-scale miners in River Nile state, are then moved into a processing plant using diggers and conveyor belts. Only a handful of insiders are privy to how much gold the tightly guarded operation produces, who it is sold to or where it ends up because no public records are available.

Commercial Registry documents seen by Bloomberg provide the first evidence that the compound is owned by Meroe Gold, a company the U.S. Treasury says has ties to the Wagner Group, which it describes as a mercenary company connected to the Russian Ministry of Defense. In addition to access to lucrative mineral deposits, Meroe has licenses to operate in Sudanese industries ranging from transport and agriculture to plastics, the documents show.