David Beckham had to strip to his underwear in front of tough guy director Guy Ritchie last month (Oct12) - the Snatch filmmaker is shooting the soccer star's latest pants promo.

The sports hero was caught running around a woodland area half-naked by celebrity-hunting fans on a tour of Los Angeles as he shot his latest campaign for his H&M underwear range.

But at least the advert, which is set to air next year (13), will have a macho edge - Ritchie is behind the camera.

A source tells Britain's The Sun, "Those pictures of a tour bus copping (getting) an eyeful of David in green pants is all for the ad.

"It's like a short action movie shot in typical Guy Ritchie style."

The Sherlock Holmes filmmaker has previously helmed adverts for French fashion house Chanel and sports giant Nike.