Amy Winehouse has stunned the media with another display of erratic behaviour - the singer was pictured with white powder inside her nose after turning her car into a public changing room. The British star emerged from her London home on Wednesday (05Dec07) night with a clearly-visible white residue, believed to be cocaine, inside her nostrils and climbed into an awaiting car. Once inside the vehicle, Winehouse then proceeded to change her trousers - in full view of photographers. Earlier on Wednesday, the Rehab singer had denied reports she is using drugs, after photos of a "bag of white stuff" in the boot (trunk) of her car emerged. In a statement, Winehouse explained the contents of the bag were "the driver's hand towels". Doctors recently ordered the 24-year-old to cancel the remaining dates on her U.K. tour and withdraw from any promotional commitments until the beginning of 2008 - to allow her to "take complete rest and deal with her health issues".