Campbell entered the plea Monday in U.S. District Court.
Campbell entered his plea, verified his signature on a plea form and was released after being fingerprinted and photographed.
Earlier in the day he showed up unexpectedly in a conference room at the U.S. Attorney's Office where prosecutors were announcing the indictment.
As soon as prosecutors finished, Campbell denied the charges and said he never took one penny illegally.
Court observers said his appearance at the news conference was a clever ploy.
"It's a great way to steal the government's thunder. He's going to be right in their face. That's the way this case is going to be," said defense attorney Bruce Harvey, who is not involved in the case.