During Kilimnik's time working for Manafort in Kiev, he had served as a liaison for Manafort to the Russian aluminum magnate Oleg Deripaska, with whom Manafort had done business. Emails previously described to The Post show that Manafort asked Kilimnik during the campaign to offer Deripaska "private briefings" about Trump's effort. A Deripaska spokeswoman has said the billionaire, a close ally of Russian President Vladimir Putin, was not offered and did not receive such briefings.