PHOENIX -- An Anthem doctor accused of sexual exploitation of a minor has pleaded not guilty in the case.
Maricopa County prosecutors say Dr. Lewis Underwood entered his plea Thursday. His next scheduled court date is May 15.
Authorities say Underwood was arrested in December 2010 on suspicion of molesting a former employee's then 9-year-old son.
County Sheriff's investigators say the boy told his mother that he and Underwood played a ``tickling game'' while at the doctor's home.
They say forensics on Underwood's home computer and other evidence taken from his residence unearthed more than 88,000 images and 1,500 videos of child pornography.
Investigators say they found photographs of the ex-employee's son naked and taken in a backyard pool.
Underwood was eventually charged with 11 counts of sexual exploitation of a minor.