Why do you think the information came "from inside the campaign"?
The F.B.I. obtained phone records and other do ents using national security letters — a secret type of subpoena — officials said. And at least one government informant met several times with Mr. Page and Mr. Papadopoulos, current and former officials said. That has become a politically contentious point, with Mr. Trump’s allies questioning whether the F.B.I. was spying on the Trump campaign or trying to entrap campaign officials.
https://www.nytimes.com/2018/05/16/u...stigation.html