"People are saying that I'm being 'Clintonesque', that I'm waiting until I know everything I have to deal with so that I can figure out what I have to lie about," he said on his radio program. "I am waiting to find out just exactly what I am facing legally."
According to law enforcement sources, Limbaugh is part of a black market prescription drug investigation in South Florida.
The claim he may have abused the prescription painkiller Oxycontin, as CBS News Correspondent Byron Pitts reports, puts a spotlight on an issue the Drug Enforcement Agency calls the fastest growing epidemic in America.
"Oxycontin will get you hooked real quick," says Richard, a former drug user, who asked to remain anonymous. "I lost two businesses. I lost two wives."
But Richard, a former drug counselor, says he was addicted to Oxycontin. It gave him the same high as heroin.
"A good bag of heroin (could last) maybe three to four hours, then you're going to get sick," says Richard.
Oxycontin, on the other hand, will last 12 hours and is cheaper than heroin, says Richard.
Oxycontin is legal - used properly by patients everyday.
"It's used primarily with cancer victims and with people with chronic back pain, for example," says Peter Provet, of Odyssey House, a substance abuse rehabilitation center. "It's a strong medication. It's typical dosage is one every eight hours. Most other pain medications are used once every two to four hours."
The misuse of Oxycontin first exploded in Appalachia when addicts discovered they could crush the pill creating an instant and intense high . It eventually spread to suburbia.
The misuse of Oxycontin has become so serious that even the manufacturer, Purdue pharmaceutical, created a public service announcement saying that 4 million Americans abuse or misuse prescription drugs each month.
Following lawsuits and pressure from Congress the company is developing a so-called 'smart tablet' technology, which could make snorting or injecting painkillers like Oxcontin impossible.
FDA approval for that is still pending. So for now, the dangers are still real.
As for Rush Limbaugh and his connection to Oxycontin, law enforcement sources say a move in the case could come soon.
Editors Note: An earlier web version of this story reported that "In one year, in Broward County, Fla., Oxycontin abuse killed more people than heroin." This statistic cannot be confirmed, and has been removed from the story.