Florida investigators have raided Rush Limbaugh’s doctors’ offices and seized his medical records in the first sign the radio jock could face criminal charges for buying black-market drugs.

The blockbuster development was revealed yesterday in search warrants that accused Limbaugh of “doctor shopping” to find a steady supply of under-the-counter painkillers.

“Mr. Limbaugh’s actions violate the letter, and spirit” of the law, said one of the warrants on file at the Palm Beach County courthouse.

Limbaugh lined up four doctors to provide him with “controlled substances” and “alternated physicians to obtain overlapping prescriptions,” according to warrants that were issued on Nov. 25 before cops raided the offices in West Palm Beach and Jupiter, Fla.

The right-wing radio jock has not been charged with a crime. In an apparent bid to blunt the impact of the revelations, Limbaugh said on his syndicated show yesterday that prosecutors were on a “fishing expedition.”

“Let us make our position clear: Rush Limbaugh is not part of a drug ring,” Limbaugh said, reading from a script prepared by defense attorney Roy Black. “We won’t speculate on why the state attorney’s office is handling Mr. Limbaugh’s case the way it is.”

The Palm Beach County states attorney, whose painkiller probe ensnared Limbaugh, issued a statement saying only that “all medical records have been obtained by court sanctioned search warrants.”

New York criminal defense attorney Louis Aidala said it appears investigators are building a case specifically against Limbaugh that could be brought before a grand jury.

“There will be a decision made whether to prosecute,” Aidala said. “I would guess that Mr. Limbaugh is having a few sleepless nights.”

Limbaugh, who recently fessed up to being a painkiller junkie, denied doing anything criminal yesterday and said he was being singled out because of his “prominence and well-known political opinions.”

Limbaugh, who lives in a $24million Palm Beach palace, went into rehab for five weeks in October after the probe was revealed. He admitted being hooked on prescription painkillers, including OxyContin and Hydrocodone, which he took for back pain.