Lindsay Lohan (who turned down a role in The Hangover) denies she stole the recipe for her tanning line, as alleged in a lawsuit filed against her.

"No formula was stolen for Sevin Nyne!" the actress -- who just turned 23-years-old -- Tweeted. "It's a woman looking for a payday. That's it!"

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Scientist Jennifer Sunday filed a federal lawsuit against Lohan and her business partner, Lorit Simon, for breach of contract, theft of trade secrets, civil conspiracy, intentional interference with contractual relations and deceptive and unfair trade practices.

See photos of too-tan stars.

Lohan takes credit for co-creating the spray tan mist -- named after her lucky numbers, and sold for $35 at Sephora -- with Simon, a Las Vegas-based businesswoman.

The lawsuit alleges Simon and Sunday were negotiating over samples of the product, but couldn't agree on a price.

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"The next thing we know, Lorit Simon and Lindsay Lohan are partnering, and Ms. Lohan is taking credit for developing this formula, which she indeed had no role in," Sunday's lawyer, Marcia Cohen, told the St. Petersburg Times yesterday.