AP Photo/Manuel Balce Ceneta
- GOP Sen. Chuck Grassley published an FBI document containing an unverified allegation made by a Ukrainian CEO.
- The Ukrainian executive boasted he'd bribed Joe and Hunter Biden, an FBI informant claimed.
- FBI told Insider the release of the document "at minimum — unnecessarily risks the safety of a confidential source."
The FBI on Thursday blasted two top Republican lawmakers for supporting the release of an internal investigative document that contains unverified allegations that President Joe Biden and his son Hunter accepted bribes from a Ukrainian gas company — claims the White House called "dishonest" and which even some Republicans have cast doubts on.