The Daily News - quoting a story it says was sold by Limbaugh's maid to the National Enquirer - says she claims he had her buy drugs for him, and gave her tens of thousands of dollars to keep quiet about it, saying it would ruin him if the story became public.
According to the Daily News, the maid - Wilma Cline, 42 - told the Enquirer that she eventually went to prosecutors and wore a wire to collect evidence for the investigation.
The Daily News reports it has independently confirmed that Limbaugh is under investigation by the office of the Palm Beach County, Fla., prosecutor.
Mike Edmondson, a spokesman for the prosecutor's office, said early Thursday that he could neither confirm nor deny that a probe is under way.