The warning came after the FBI raided his home in July, even picking the lock, although he was at home asleep, the Times reported, citing two sources close to the investigation. Agents sought proof he had set up offshore bank accounts, and, the Times says, they took photos of the expensive suits in Manafort's closet.
On Monday, CBS News confirmed Manafort had been wiretapped under a foreign intelligence warrant in connection with U.S. concerns that he was communicating with Russian operatives who wanted to influence the American election. The warrants were issued before Robert Mueller was appointed as special counsel to take over the investigation from the FBI.
The U.S. government listened in on Manafort's conversations during the presidential campaign and through the election -- though not constantly -- and its surveillance includes the period when Manafort was Mr. Trump's campaign chairman.
CBS News' Andres Triay contributed to this report.
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