LOUISVILLE, Ky. — It’s the largest health care fraud case in US history and a Louisville doctor is involved. Christopher Nelson was indicted on federal charges earlier this week. He owns Bluegrass Pain Consultants in Louisville.

Investigators said Dr. Nelson paid his staff bonuses based off of the number of drugs they prescribed to patients. He also got a higher sales commission from the drug company.

Now WHAS11 is digging deeper into that doctor’s past.  

Dating back more than a decade, Nelson has faced at least eight patient complaints to the medical board.

The first was in 2002 when Nelson was noted for lying on his application to the state medical licensing board. According to documents, he failed to report a history of alcohol abuse and treatment on his application. For that, the board sent him a "letter of concern." He license was approved.

In the years that followed, the health care professional was accused of putting patients wellbeing on the back burner. First in 2006 and then 2007, 2009, and twice in 2012.

Patients reported their concerns to the Kentucky Board of Medical Licensure and accused the doctor of unethical or unprofessional conduct.

One patient alleged Nelson did not provide appropriate treatment for her pain. Another patient reported Nelson to the board when the doctor refused to fill a prescription. Other accusations included the doctor failing to provide quality care and failed to treat the patient with respect.

Every accusation was ruled "without merit" and the cases were closed.

In 2013 the doctor was reported again.          

First for what the patient called "unprofessional conduct" and later in the year for a "poor standard of care."

One case was dismissed, the other acknowledged with another "letter of concern."

Through the series of accusations and “letters of concern,” the doctor kept his license and his business.

Nelson continued operating Bluegrass Pain Consultants in Louisville until last year when FBI agents were seen raiding the facility and leaving with boxes of evidence.