LATEST: The recording of Britney Spears' video appearance for Madonna's latest world tour has been delayed due to technical problems.
The pop superstar had reportedly asked Spears earlier this month (Jul08) to make a promo that would air during her Sticky + Sweet tour, in a bid to help the troubled star resurrect her own singing career.
But the Toxic singer's scheduled recording slot on Tuesday (08Jul08) was derailed as the set for the top secret video was not completed in time.
The set features an elevator on which Spears will perform, a source tells E! News online.
The insider adds, "The video will be very deep. You've never seen Britney like this before. It will blow your mind."
Madonna's publicist Liz Rosenberg confirmed Spears will record footage for the tour, but insisted the details of her appearance are "a secret".