ABC reports that Hastert is under investigation:

The Speaker of the U.S. House of Representatives, Dennis Hastert, is under investigation by the FBI, which is probing corruption in Congress, ABC News reported on Wednesday.
ABC, citing high level Justice Department sources, said information implicating Hastert was developed from convicted lobbyists who are now cooperating with the government.

But the Justice depart says no:

The Justice Department denied a news report Wednesday that it was investigating House Speaker Dennis Hastert.
The statement by department spokeswoman Tasia Scolinos came in response to a report by ABC News that Hastert was under investigation by the FBI to determine his role in a public corruption probe centered around convicted lobbyist Jack Abramoff.
…
Hastert’s office later issued a statement calling the ABC report “absolutely untrue” and demanding a full retraction. ABC had no immediate comment.

The Justice department or ABC News, which do we believe? Hmmmm…
(Link via Drudge Report)