A former Wal-Mart vice president pleaded guilty Monday to three counts of wire fraud, admitting that he manipulated invoices to embezzle money that was funneled to a senior executive.

Robert E. Hey Jr. had reported to Thomas Coughlin, a former Wal-Mart vice chairman who is under investigation by the U.S. Attorney’s Office. Wal-Mart referred Coughlin to federal prosecutors this year alleging he had defrauded the company out of $500,000; Coughlin has not been charged.

Wal-Mart, the world’s largest retailer, and Coughlin’s attorney, William Taylor III of Washington, both declined comment.

Wal-Mart this year sued to void Coughlin’s multimillion retirement package, saying it had evidence that Coughlin had defrauded the company.