CNN's sources suggested that some of the evidence "sparked concerns among investigators that Manafort had encouraged the Russians to help with the campaign", but that the evidence of Russian collusion remained inconclusive.
However, the Foreign Intelligence Surveillance Act (FISA) warrants were granted before his investigation started, and were first authorised as part of an investigation into Washington consulting firms working for Ukraine, CNN reported. The F.B.I. later obtained a new FISA warrant, which reportedly extended into early 2017 and was part of the probe into whether members of the Trump campaign worked with the Kremlin to derail Hillary Clinton's candidacy. Despite Manafort resigning as Trump's campaign manager in August 2016 due to reports about his connections to the Vladimir Putin regime, the two men remained in touch even after Trump was elected president.
It does not seem that Manafort was wiretapped while he served as Trump's campaign chairman.
Mr. Manafort is under investigation for possible violations of tax laws, money-laundering prohibitions and requirements to disclose foreign lobbying. Kremlin spokesman Dmitry Peskov stressed that Russian Federation did not cooperate with President Trump's staff during the election campaign.
Now, based on recent revelations offering an insight into the direction in which the probe is headed, experts claim that Mueller's probe has reached a critical stage - to the extent that they believe the former Federal Bureau of Investigation director might soon make allegations in public.
New details about a July FBI raid at Paul Manafort's home in Virginia shine a new light on the tactics Robert Mueller is using in his investigation of the Trump campaign's ties to Russian Federation. Manfort was Donald Trump's campaign manager at the time of the 2016 U.S. presidential elections. But if Trump was incidentally picked up on the Manafort wiretaps, perhaps he should have been a little more judicious about his choice of advisers.More news: Digital Payment Bound To Pick Up With New Technology
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The intercepts were part of a wide-ranging Federal Bureau of Investigation counter-intelligence operation.
The CNN report also noted that Manafort has a residence in Trump Tower, although it said it was "unclear" whether the wiretapping took place there or not.
Neither Manafort nor Mueller commented for either the CNN or NYT stories.
The president can complain all he wants about investigations of his associates.