In the proposed class-action lawsuit filed in Brooklyn federal court, plaintiff Chris Shake said the snacks actually contain corn and oils made from genetically engineered plants.

Shake said he shelled out an additional 10 cents per ounce of chips to buy the allegedly "all-natural" Tostitos and SunChips instead of a product such as Doritos, which makes no such claim.

Independent testing conducted on samples of Frito-Lay products labeled "all natural" uncovered the presence of ingredients - including corn and vegetable oils - made from genetically modified plants, the lawsuit said.

Had he known that, Shake would never have paid a premium to purchase the "all-natural" chips, the lawsuit said, calling Frito-Lay's labels "deceptive."

A spokeswoman for Frito-Lay, Aurora Gonzalez, said the company was confident the labeling on its packaging "complies with all regulatory requirements."

But according to the suit, "genetically modified organisms are created artificially in a laboratory by swapping genetic material across species to exhibit traits not naturally theirs," the complaint said. "Since a reasonable consumer assumes that seeds created in such a way are not 'all natural,' advertising Tostitos and SunChips as natural is deceptive and likely to mislead a reasonable consumer."

A similar lawsuit was filed in California federal court last December. Both the New York and California lawsuits are seeking to recover the amount of money allegedly paid by consumers in search of an "all natural" product.

The New York lawsuit estimates the amount of total damages to exceed $5 million.

Frito-Lay is a unit of PepsiCo Inc.

According to the Center for Food Safety, there is no comprehensive, formal definition of the term "natural" when it is used on food labels, with the exception of some meat products regulated by the U.S. Department of Agriculture.

In 2011, the Center for Food Safety petitioned the U.S. Food and Drug Administration to require food containing genetically modified ingredients be clearly labeled.

The case is Shake et al v. Frito-Lay North America Inc and Pepsico Inc, in the U.S. District Court for the Eastern District of New York, No. 12-408.

(Reporting by Jessica Dye; editing by Gary Hill and Andre Grenon)

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