Chicago ? Amid controversy, a criminal investigation and a wellspring of support, conservative radio talk show host Rush Limbaugh is scheduled to return to the air today, 38 days after entering treatment for a self-described addiction to prescription painkillers.

“Monday will be a very big day,” said Michael Harrison, editor and publisher of Talkers magazine, a radio industry trade publication. “The biggest star in the business is coming back from one of the most publicized struggles in recent memory.”

Limbaugh remains under investigation by law-enforcement officials in Florida, where the punishment for possession and use of unlawfully obtained prescription drugs can be up to 30 years in prison.

It is still an open question whether Limbaugh, who has often prided himself on straight talk and honesty, will address the investigation. Before leaving the air, he declined to comment on the charges, telling his listeners only, “the stories you have read and heard contain inaccuracies and distortions, which I will clear up when I am free to speak about them.”

“The first thing you do is what your lawyer says,” said Jim Bohannon, the politically moderate host of “The Jim Bohannon Show,” which is distributed by the Westwood One radio network, a competitor of Limbaugh’s syndicator, Premiere Radio Networks. Bohannon predicted Limbaugh would be uncharacteristically reticent on his legal situation.

“Certainly it would be at variance with the way he’s been in the past — he’s a talk show host, for Pete’s sake.”

On Oct. 10, Limbaugh told his listeners he had become addicted to painkillers prescribed after spinal surgery, and that he was checking himself into a drug treatment facility to “once and for all break the hold this highly addictive medication has on me.”

The announcement came eight days after the supermarket tabloid The National Enquirer reported that Limbaugh, who lives in Palm Beach, Fla., was under investigation by the Palm Beach County state attorney for allegedly buying thousands of pain pills, including the powerful drug OxyContin, from his housekeeper.

While the state attorney’s office refused to officially confirm initial reports, a Florida law-enforcement source said last week that an investigation into Limbaugh’s activities was ongoing.