Atlanta could owe back pay to employees who worked overtime last year, according to a new report from the city auditor’s office.

In a review of timekeeping records for the first 21 pay periods of 2014, auditor Leslie Ward found that the city might owe employees for nearly 200,000 hours that workers clocked in beyond their typical work week.

What’s more, when the city did pay for overtime, it might have paid too little to some, she said. The audit found that Atlanta appears to have paid more than 7,500 hours that should have been overtime at workers’ regular rate, instead of time and a half.

But Ward says it's hard to tell because workers record time and are paid via separate systems, noting that manual corrections could have been made in payroll records without correcting the timekeeping system.

Her office didn’t calculate the potential financial impact of those hours, as earnings vary. But if each worker earned just minimum wage, and was reimbursed at time-and-a-half, the city would be on the hook for more than $2 million in back pay.

Some of the unpaid hours could be due to employees improperly entering time, she notes. Still, the report casts doubt on Atlanta’s compliance with federal laws. For example, some departments reported that employees aren’t paid for overtime if not approved in advance.

“We concluded that we certainly are at risk for violation of the (Fair Labor Standards Act) because of the way time has been recorded in the city system,” she said. “Generally, if it’s worked, it has to be paid, but what we heard people say contradicted that.”

A spokeswoman for Mayor Kasim Reed’s office said his administration is committed to ensuring that all employees are properly compensated in accordance with state and federal laws. The city’s human resources and legal departments are now working to determine which employees are entitled to back pay, spokeswoman Jewanna Gaither said.

His administration agreed with each of Ward’s 11 recommendations. Gaither said that, prior to the report, the administration had already begun to implement new controls to “alleviate the issues of owing pay to some employees” and “improper timekeeping practices being exercised by some employees.”

It’s the latest audit to point to questionable compliance with federal laws and regulations. Previous reports from Ward’s office raised concerns about the city’s travel reimbursement practices, how well it complies with IRS payroll tax requirements and keeps track of take-home vehicles.

The audit, which was prompted by multiple calls to the city’s “integrity line” about abuse of the city’s automated timekeeping system, also reported concerns about theft of time. Timekeepers in nine departments reported problems, including time clocks that were vandalized or unplugged, and employees punching time cards for others.

Ward’s report did not focus on how many city employees were compensated for hours they did not work.