(CNN)California’s insurance commissioner has launched an investigation into Aetna after learning a former medical director for the insurer admitted under oath he never looked at patients’ records when deciding whether to approve or deny care.

California Insurance Commissioner Dave Jones expressed outrage after CNN showed him a transcript of the testimony and said his office is looking into how widespread the practice is within Aetna.

"If the health insurer is making decisions to deny coverage without a physician actually ever reviewing medical records, that’s of significant concern to me as insurance commissioner in California — and potentially a violation of law," he said.

Aetna, the nation’s third-largest insurance provider with 23.1 million customers, told CNN it looked forward to "explaining our clinical review process" to the commissioner.

The California probe centers on a deposition by Dr. Jay Ken Iinuma, who served as medical director for Aetna for Southern California from March 2012 to February 2015, according to the insurer.

During the deposition, the doctor said he was following Aetna’s training, in which nurses reviewed records and made recommendations to him.

Jones said his expectation would be "that physicians would be reviewing treatment authorization requests," and that it’s troubling that "during the entire course of time he was employed at Aetna, he never once looked at patients’ medical records himself."

"It’s…