For a decade, Venezuelan businessman Alejandro Betancourt has been ensnared in the tentacles of a sprawling Justice Department probe into a sophisticated billion-dollar money laundering scheme that US prosecutors allege embezzled funds from Venezuela’s state-owned oil company known as PDVSA.

In recent months, federal prosecutors in Miami closed the Betancourt investigation on orders from the office of then-Deputy Attorney General Todd Blanche, they were told, according to two people briefed on the matter. The move came as part of an effort by Trump White House officials and Secretary of State Marco Rubio to enlist Betancourt to engineer a massive new oil deal with Venezuela’s government, the people briefed on the matter said.

After years of failing to persuade prosecutors in the US, Spain and Switzerland to move on from their criminal investigations into him, Betancourt’s biggest break came after the US military in January snatched Venezuelan leader Nicolás Maduro from his home in Caracas and brought him to New York to face narco-trafficking charges. Within hours, Betancourt’s phone rang and administration officials sought his help to begin discussions with officials in Maduro’s government who remain in charge, led by his vice president Delcy Rodríguez, according to multiple people familiar with the oil deal.