Has anyone heard an acapella version of "Rocks" covered by Sugababes?

A couple of years ago I watched a doentary on ITV (in the UK) about the Sugababes and at the end they sang an acapella cover of Rocks (Originally by Primal Scream). I would really like to hear this song again so if anyone knows where I can find it on the Internet I would be very grateful. There are some cover versions on YouTube but not the acapella one that I'm after...