The latest revelation about the scale of U.S. wire tapping may add to the intrigue surrounding Firtash's ties to Manafort, with whom he discussed a New York real estate deal in 2008. Though Manafort is not named in the Chicago case, his home was raided as part of special prosecutor Robert Mueller's investigation of alleged ties between the Trump campaign and Russia, and he spent the better part of a decade advising ousted pro-Russia Ukrainian President Viktor Yanukovych, to whom Firtash was a key supporter.