Nestle USA says its baking unit has voluntarily recalled Toll House refrigerated cookie dough products after a number or illnesses were reported by those who ate the dough raw.

The federal Centers for Disease Control said its preliminary investigation shows "a strong association" between eating raw refrigerated cookie dough made by Nestle and the illnesses of 65 people in 29 states whose lab results have turned up E. coli bacteria since March.

Dr. Coomer's Blog: Cookie Dough Q & A

The FDA advised consumers to throw away any prepackaged, refrigerated Nestle Toll House cookie dough products in their homes. Retailers, restauranteurs and employees at other food-service operations should also not sell or serve any of the products.

Nestle spokeswoman Roz O'Hearn said "this has been a very quickly moving situation," adding the company took action less than 24 hours after hearing of the problem.

Officials are now looking into how these products became contaminated.

Dr. Philip Tierno, director of clinical microbiology & immunology at New York University Langone Medical Center said it could be a number of things.

"The E. coli outbreak could be from one or a number of contaminates, such as the milk component, the machinery, even the harvested flour," he told FOXNews.com in an email.

"Whether eaten or handled (causing cross contamination) the dough is a danger, especially to the elderly or anyone with a suppressed immune system," he said.

The recall includes refrigerated cookie bar dough, cookie dough tub, cookie dough tubes, limited edition cookie dough items, seasonal cookie dough and Ultimates cookie bar dough. It does not affect any other Toll House products.

E. coli is a potentially deadly bacterium that can cause bloody diarrhea, dehydration and, in the most severe cases, kidney failure.

The Associated Press contributed to this report.