High School Musical star Ashley Tisdale’s rep, Scott Appel, slammed online reports that she has been diagnosed as HIV positive. “The story is completely untrue,” Appel tells Us.

Internet rumors swirled Thursday after a web site posted a false report that Tisdale had contracted the disease from her rhinoplasty procedure last year.

The fake report alleged that a spokesman for the hospital revealed in a statement, “‘Ashley and her family are trying to come to terms with this horrible development. They only ask that you pray for Ashley’s health and to please respect their privacy as the family decides on the next course of action.’”

“We did not release any statement regarding Ashley Tisdale,” Cedars-Sinai spokesperson Simi Singer tells Usmagazine.com.

Tisdale (who topped Us’ Best Makeover List last year) plays spoiled rich girl Sharpay Evans in the hit Disney movie series High School Musical. She’s currently in Salt Lake City, Utah filming HSM3.