TMZ has obtained a lawsuit filed by Reese Witherspoon claiming Star Magazine invaded her privacy by publishing a "fictional" story that the actress was pregnant.

In the lawsuit, filed Wednesday in Los Angeles County Superior Court, the Academy Award-winning actress claims the magazine published a false story that she was pregnant "in a callous effort to boost the tabloid's sagging sales."

"Contrary to the fabricated Cover Story," the lawsuit says, "the true facts are that [Reese] is not pregnant, does not have a 'baby bump' and has not otherwise gained weight such that she has had to resort to wearing 'Empire-waist dresses,' 'baggy clothing,' or an 'old-fashioned 1920's bathing suit.'"

Reese also alleges in the suit that "this fabricated tall tale was brazenly published as a prominent and conspicuous cover story for the purpose of garnering the maximum attention to the tabloid..."

The lawsuit claims the story was a violation of Reese's privacy and portrays her in a false light. It seeks unspecified damages.

Mike Kahane, General Counsel for American Media, told TMZ, "It is a frivolous lawsuit. It has no legal merit and we intend to vigorously defend it and have every confidence that we will prevail."

We asked Kahane if Star believes Witherspoon is pregnant. He said, "The article asks the question as to whether or not she is pregnant based on her physical appearance and clothing that she was wearing and we believe we have every right to ask that question."