LiLo 'avoiding Scream 5 cameo scene filming over fear of public ridicule'

But over the past two weeks - as the date for filming approached - Lohan disappeared, blew off rehearsals, missed her flight to the set and even bizarrely claimed that she had walking pneumonia, the New York Post reported.

Lindsay Lohan.Pic/Santa Banta

According to sources, the troubled starlet "freaked out" after seeing the script was poking fun at her.u00a0u00a0Apparently, Lohan did report for work, but only after she had been threatened with a lawsuit by a Hollywood lawyer and a private jet was sent to pick her up.

"Lindsay missed every meeting she had for the film, including script reads and wardrobe meetings," a source said.u00a0"Then she missed her flight to Atlanta on Sunday to shoot the movie.

"The producers had been getting signs Friday that she was a mess, and would not be fit to work," the source said.u00a0Multiple sources said that Lohan decided she didn't want to do the film because she thought her scene made too much fun of her.

"It went pretty hard at Lindsay," the source said, adding that the script featured a kiss scene with Sheen, and that "she'd been freaking out about it for weeks."

But when a call was scheduled to discuss the script, Lohan missed that, too, sources said.u00a0Yet another source said that last weekend she began saying she couldn't do the film because she had "walking pneumonia," and went to a hospital Sunday to get her lungs checked.

"She is under contract - so to get out of it, she had to prove that she was sick," said a source.u00a0The source said that Lohan tried to prove that she had walking pneumonia she had to go to hospital.

"She's been locked up in her room at the Bowery Hotel. She's been in a tailspin," another source said.u00a0"Even Charlie Sheen worried she might not be able to do the scene," the source added.u00a0However, a rep for Lohan said that these stories are untrue, and she is willingly fulfilling all of her obligations.