A new audit shows that a physician contracted by the state Department of Public Safety to provide services to five prisons over-billed taxpayers by more than half a million dollars between 2011 and 2014.

The report, by State Auditor Beth Wood’s office, recommends that DPS seek reimbursement from the physician and that the department also should consider reviewing the physician’s time records before July 2011 to determine if additional over-billings occurred.

The auditor’s findings have been referred to the N.C. State Bureau of Investigation and the Wake County District Attorney’s office.

Dr. Sami Hassan, president of North State Medical Associates in Oak Ridge, signed a request for personal services contract in June 2011 with the state. In 2013, the contract was extended by a year. The department, then called the Department of Correction, agreed to compensate Hassan at a rate of $125 an hour.

According to the report, the Department of Public Safety realized there was a discrepancy between the physician’s time records and the gate logs.

Over the three-year period, the DPS paid the physician $1.1 million for 8,864 hours. However, investigators could only analyze 6,198 hours of the 8,864 because of incomplete records.

The report says that of the 6,198 hours reviewed, the physician was at one of the corrections facilities only 1,661 of them — or 27 percent of the hours he claimed. Hassan billed the department for 4,537 hours he was not on site, totaling $567,125 in excessive billing.

However, the report says the physician had a “tacit agreement” with the department to bill for more hours than he was on site. “He said DPS administrative personnel had actual knowledge he billed DPS for more hours than he worked at the prisons,” the report says. “The physician said he routinely billed DPS approximately eight hours for a large facility and three hours for a small facility each visit.”

Department administrators denied having such an agreement in place, the report continues.

However, the report shows that one prison employee said she was told by supervisors to sign the physician’s time records even though she knew they were inaccurate. And two prison employees responsible for approving the physician’s time records said they were told by supervisors not to verify hours because it was difficult to find physicians to work at prisons.

In their response to the report, DPS Secretary Frank Perry and Division of Correction and Juvenile Justice Commissioner David Guice say they plan to follow the auditor’s recommendations.

They say that DPS is exploring avenues for reimbursement and plan to appoint a review team to review available records. Perry and Guice say that measures are in place addressing the need for accountability on time records and that any employee who doesn’t follow policies and procedures will face disciplinary action. In addition, the department’s review team will review other contracted physicians’ time records for compliance.

The prisons involved were the North Piedmont Correctional Center for Women and the Davidson Correction Center in Davidson County, the Albemarle Correctional Institution in Stanly County, and the Brown Correctional Institution and Lanesboro Correctional Institution in Anson County.