Katherine Heigl is quickly earning the reputation for being one of Hollywood’s most difficult divas.

The Grey’s Anatomy star has come under fire on the set of her latest movie Five Killers for being “extremely unprofessional,” flaking on meetings and making ridiculous demands.

Apparently the 30-year-old star has been demanding that she be flown by private plane to and from the film’s international locations, and has also requested “crazy amounts of security."

But the rumors hardly end there.

According to an extra on the film 27 Dresses, "Heigl reportedly refused to film any scenes until her pregnant assistant ran around and got her a Coke Zero. She refused to eat lunch next to anyone or have anyone speak to her once the cameras stopped rolling."

“No one on the crew likes her,” an inside source said.

“She has a sense of entitlement that is really off-putting,” another source learned. “Many directors that she’s worked with in the past do not want to work with her again.”

Heigl made headlines earlier this year when rumors began swirling that she was desperate to get off the Grey’s cast — the show that made her a household name. She has also publicly badmouthed the Judd Apatow film Knocked Up, which brought her significant box office success.

And when Heigl was up for an Emmy last year, she withdrew her name from consideration and took a dig at the show’s writers, saying she didn’t feel her character had any “material that was worthy to submit.”

LINK: Click here for more from Perez Hilton.