http://www.wsj.com/articles/secret-recordings-fueled-fbi-feud-in-clinton-probe-1478135518
Within the FBI, some felt they had moved well beyond the allegations made in
the anti-Clinton book. At least two confidential informants from other
public-corruption investigations had provided details about the Clinton
Foundation to the FBI, these people said.
The FBI had secretly recorded conversations of a suspect in a public-
corruption case talking about alleged deals the Clintons made, these people
said.