Clinton on stage with Wal-Mart founder Sam Walton

She doesn't talk about it in her speeches - or her autobiography, or the official bio on her campaign website - but Hillary Clinton was a board director of the controversial retail giant Wal-Mart for six years. Footage released on Thursday shows the presidential hopeful at a store opening in 1991 with floods of praise for the company. Wal-Mart founder Sam Walton calls her a "great friend of ours."

Wal-Mart has faced huge criticism and a string of lawsuits in the past few decades. The Arkansas-based company has been accused of providing poor working conditions and low wages, as well as using child labour overseas, so it's no surprise that Clinton doesn't advertise her time on its board of directors. But on Thursday the Center for Public Integrity, a journalistic watchdog, released parts of footage from what it calls a "mammoth archive" covering the then Arkansas First Lady's time with the company from 1986 to 1992. The clip shows Clinton and Walton congratulating each other while Clinton describes a new store as "gorgeous" and jokes that she "wants to shop!"