The move comes after an investigation into the commentator that began over two years ago.

Limbaugh admitted on air in October 2003 he was addicted to prescription painkillers after Florida authorities began an investigation into him.

The problem stemmed from spinal surgery several years ago and he has sought treatment for it, he said.

Limbaugh, 55, was charged with illegally obtaining prescriptions, or "doctor shopping", after presenting himself at the Palm Beach county sheriff 's office.

He was later released on $3,000 ( 2,375) bail, according to his lawyer, Roy Black. Black said his client had filed a written plea of not guilty and denied the charge.

But under a deal with prosecutors, the charge will be dropped in 18 months if Limbaugh continues to seek treatment for his addiction.

Limbaugh has also agreed to make a $30,000 payment to the state of Florida to offset the public cost of the investigation.

"The prosecutors and I agree that there shouldn't be a criminal prosecution, and we agree there shouldn't be any court proceedings, " Black said, adding that his client was pleased the case was over. "He's just happy that it's finally ended and he can go back to his normal life, " he said.

The case attracted widespread attention in 2003 because the popular radio commentator had been a tough critic of drug offenders.