Rush Limbaugh is out of rehab for his addiction to painkillers, but authorities are now investigating whether he skirted state money-laundering laws in getting the money to buy the prescription drugs, authorities tell ABC News.

Limbaugh, 52, who is said to earn $35 million a year, reportedly made 30 to 40 cash withdrawals from his bank, U.S. Trust -- each just under $10,000. According to IRS rules, banks must report if anyone makes a single withdrawal of more than $10,000.

A conviction on such charges in Florida would be a first-degree felony. The maximum sentence could be 30 years in prison.

Authorities will determine this week if Limbaugh, who returned to the airwaves Monday after five weeks of rehab, will face charges.

Limbaugh's lawyer, Roy Black, tells ABC News: "There's no basis for these charges. He has not committed any acts of money laundering, and he absolutely denies it."

Black went on to say, "I can assure you -- and Rush assures the listeners to his radio station -- when we can, we will tell the story, and he will tell it himself. Everybody will see what has really gone on here."