An ex-Russian spy put pressure on former Trump campaign manager Paul Manafort during the 2016 campaign on behalf of an oligarch to whom he owed “a lot of money,” TIME said in an exclusive report. Victor Boyarkin, who was recently put on a U.S. sanctions list, is considered a former Russian intelligence operative who allegedly handled money and negotiations “on behalf of a powerful Russian oligarch,” billionaire Oleg Deripaska. Manafort stands accused in the U.S. of being “deeply indebted” to Deripaska, who wanted money from a botched business deal in Ukraine, per TIME. Boyarkin said in an exclusive TIME interview that he communicated with Manafort during the presidential race on Deripaska’s behalf. “He owed us a lot of money,” Boyarkin reportedly said. “And he was offering ways to pay it back.” In spring and summer 2016, Manafort allegedly tried offering Deripaska “private briefings” on the presidential contest in order to “get hole,” according to previous reports in the Washington Post and The Atlantic. Boyarkin told the magazine that Special Counsel Robert Mueller’s office contacted him in its investigation into potential collusion between Russia and Trump’s campaign. “I told them to go dig a ditch,” he recalled saying. Sources told TIME that Boyarkin’s potential leverage over Manafort might explain why Trump’s onetime adviser weighed returning to work for pro-Russian interests after leaving the campaign in August 2016.