Online reports that High School Musical star Ashley Tisdale has been diagnosed HIV positive are “completely untrue,” her rep, Scott Appel, tells PEOPLE.

Several Internet posts Thursday said the actress/singer may have contracted the disease from her rhinoplasty procedure last year. By Friday the rumor mill kicked into overdrive causing some panicked fans to post YouTube videos to “Pray for Ashley.”

Another Internet site posted what it claimed was a statement from Cedars-Sinai Medical Center in Los Angeles.

But Cedars-Sinai spokesperson Simi Singer tells PEOPLE: “We absolutely did not issue a release.”

Ashley Tisdale is planning for a little magic in her life after High School Musical.

The actress and singer is in talks for a remake of the 1989 movie Teen Witch, Variety reports.

Best known as Sharpay in the HSM series, Tisdale, 22, would star as Louise Miller, the unpopular girl who descends from Salem witches and shares their powers. TV star Robyn Lively starred in the original.

All six of the High School Musical stars have officially signed on for High School Musical 3: Senior Year, Walt Disney Studios Motion Picture Productions announced Monday.

Zac Efron, Vanessa Hudgens, Ashley Tisdale, Corbin Bleu, Monique Coleman and Lucas Grabeel will star in the third and final installment, a feature film. The first two movies aired to a record number of viewers on The Disney Channel.

“I am the luckiest guy in the world and I know it,” Ortega says. “This will be our last time together and I love working with these kids so much. It’s going to be great.”

Tisdale, who will reprise her role as school diva Sharpay, says she looks forward to returning to East High set in Utah one last time.

“I’m excited,” Tisdale tells PEOPLE. “But it’s going to be sad. It seems like it will be graduation and I’ll be crying while we’re filming.”

According to the studio, HSM 3: Senior Year finds high school seniors Troy %26#91;Efron%26#93; and Gabriella %26#91;Hudgens%26#93; facing the prospect of being separated from one another as they head off in different directions to college. Joined by the rest of the Wildcat crew, they stage an elaborate spring musical reflecting their experiences, hopes and fears about their future.

High School Musical star Ashley Tisdale is finding herself on the defensive again after rumors surfaced last week that she had more plastic surgery.

“People are saying I had another nose job and I did not. That’s ridiculous,” Tisdale tells PEOPLE exclusively. “I was away in New Zealand filming a movie (They Came From Upstairs) and so people think I went away to have more work done. But I didn’t.”

“%26#91;Tabloids%26#93; have doctors talk about what they think I did with my surgery, but they did not examine me,” Tisdale says. “They don’t know what I have inside my nose.”

“It’s very irresponsible for a medical professional to comment on someone whom they have not examined,” notes Tisdale’s rep, Scott Appel.

Rumors also recently surfaced that Tisdale, who is in Utah to film High School Musical 3 had a breast augmentation.

“Look at me,” she says, laughing. “Does it look like it to you? No! It’s ridiculous. I’m not for plastic surgery. I’m not going to get another surgery. I can promise you that.”