Macy’s said a former employee concealed up to $154 million in delivery expenses over the course of nearly three years.

The person who allegedly hid the money is no longer with the company, the department store operator said Monday morning, ahead of its third-quarter earnings report. The company, whose statement on the matter didn’t say when the person left the job, didn’t immediately respond to a request for comment.

Macy’s said it discovered the issue while preparing its financial report for the three-month period ending Nov. 2. It was due to deliver results before U.S. stock markets opened Tuesday morning, but it has delayed releasing its full results until Dec. 11 to allow an independent investigation to wrap up

The company said the employee, who was responsible for the accounting of small package delivery expenses, “intentionally made erronenous accounting accrual entries” to hide millions of dollars from the fourth quarter of 2021 through the most recently completed quarter. Macy’s said its delivery expenses totaled around $4.36 billion during that period.