The U.S. Food and Drug Administration said samples of Nestlé Toll House refrigerated cookie dough tested positive for E. coli and they were awaiting results to find out if carries the same fingerprint as the strain that resulted in 69 people nationwide getting sick.

The cookie dough sample was taken from a 16-ounce refrigerated chocolate-chip cookie dough bar carrying a production date of Feb. 10 and best-before date of June 10. FDA spokeswoman Stephanie Kwisnek said they took the sample from Nestle USA’s Danville, Virginia plant while inspecting and the test came back positive Monday.

The Centers for Disease Control and Prevention is running tests on the positive sample expected to be completed later this week to see if it is a genetic match to the outbreak strain, Kwisnek said.

Laurie MacDonald, vice president of corporate and brand Affairs at Nestlé USA said, "Nestlé continues to work closely and in full cooperation with the FDA on the ongoing investigation. We are very concerned about those who have become ill from E. coli 0157:H7, and deeply regret that this has occurred."

Federal investigators spent more than a week at the Danville plant and did not detect contamination in the equipment or among workers, said David Acheson, assistant commissioner for food safety at the FDA. He said investigators did not find the bacterium inside the factory or on equipment but in a tub of chocolate cookie dough made at the site in February.

Acheson said. "It raises the likelihood that it was an ingredient," he said. "And it really means that industry has to be constantly vigilant, because foods we think of as low risk could be contaminated with a deadly pathogen."

Officials at the FDA and the federal Centers for Disease Control and Prevention suspected that dozens of cases of E. coli-related illness were linked to the product after interviews with patients showed a high percentage of them ate raw Nestlé's cookie dough before becoming sick. The CDC said most victims are teenage and preteen girls.

Within 24 hours after the FDA notified it about the possible connection to the outbreak Nestlé voluntarily recalled 30,000 cases of its refrigerated cookie dough on June 19. The recall doesn't include already baked Toll House products.

Till now the CDC reported 69 cases of E. coli 0157 illness linked to cookie dough in 29 states including two in Maryland and two in Virginia.  34 of the victims have been hospitalized and nine developed a serious complication known as hemolytic-uremic syndrome. None has died.

Health officials still do not know how E. coli 0157 contaminated the cookie dough because refrigerated dough has rarely been associated with any food-borne illness outbreaks. Kwisnek said, "We are working with Nestlé to find out how it [the sample] became contaminated," she said. "The investigation is still ongoing."