"Amy is not in rehab," Winehouse's representative told People.com. "She was seeing a doctor who she regularly sees as part of her ongoing treatment. It was a regular appointment which she attends all the time. She has not checked in overnight."

The representative declined to comment on what kind of treatment Winehouse was undergoing.

The Sun, a British newspaper, said Winehouse entered rehab Tuesday, the same day the paper ran on its Web site a video showing her allegedly smoking a crack pipe.

Winehouse can be heard on the video saying she had just taken six valium pills and The Sun said she consumed ecstasy and cocaine, as well, during a binge.

"We are deeply disappointed and upset by these latest revelations and are doing everything we can to offer Amy our full support in dealing with her problems," said a statement issued by the singer's label, Universal Records.