The overpayments, mentioned briefly by the school system’s outside auditor in a report made public in July, were documented in greater detail in an internal audit dated June 30. The Post obtained the internal audit through a public-records request.

Some employees were allowed to rack up “negative leave balances,” meaning they were paid for time off beyond what they were owed.

Some employees who had retired and then returned to active service under a special state program had salaries larger than allowed under law.