Four years ago, few people had ever heard of the man who had made hundreds of millions of dollars in the health care industry.

Today, Rick Scott is a seasoned politician hoping to win a second term as Florida's governor.

But now Scott is being hounded by a person from his past with one mission: to make sure he is voted out of office.

John Schilling is a whistleblower who helped the government collect the largest Medicare fraud fine in U.S. history. That $1.7 billion fine was paid by Columbia HCA, the health care company once led by Scott.

Scott was forced out of Columbia in 1997, just after the Medicare fraud investigation began, but he was never charged with wrongdoing.

Schilling is in Tallahassee to speak out about what he says were massive overcharges. Bills sent to the federal government for Medicare services Columbia either didn't provide or wasn't supposed to provide.

Schilling said he worries the same kind of thing could be happening at the state Capitol.

"He was running a company, a multi-billion dollar company, and ignorance is no excuse," he said. "I mean, you have to know what's going on within your organization, and do we want someone to govern our state that doesn't know what's going on in our government?"

Whether it's the front office or a health care company or the governor's office in Florida, Schilling's message is clear: Rick Scott can't be trusted.

Scott's rocky tenure at Columbia is as well known today as it was four years ago when he first ran for governor. As a result, Republicans are calling Schilling's visit a political stunt.

The Scott campaign says Schilling's assertions are right in line with an attack ad being run by Democrats. They call it proof that "no one's buying" what Democrat Charlie Crist "is selling."

"It's interesting, when people get desperate, the things they say," Scott said. "I mean, that's absolutely silly."

But Schilling is a Republican who says he's only campaigning against Scott because of what he learned 20 years ago at Columbia.