Wal-Mart and Mercury Public Affairs have ended their business relationship, the Los Angeles Times reported Friday night.

More than a week ago, a junior employee at the agency was caught going undercover at a meeting of Warehouse Workers United, an employee group critical of Wal-Mart. The Bentonville, AR-based company hired Mercury to lobby city hall officials as it sought to build a store in Los Angeles' Chinatown section.

Mercury told PRWeek last week that Stephanie Harnett, the 23-year-old associate at Mercury who reportedly posed as a student journalist, was no longer working at the firm. Executives at the agency condemned her actions.

A Wal-Mart spokesperson told the LA Times that the retailer and Mercury mutually decided to stop working together.