The Food and Drug Administration said yesterday that a sample of raw cookie dough collected at a Nestlé USA manufacturing plant in Virginia last week has tested positive for E. coli.

Nestle voluntarily recalled all Toll House refrigerated cookie-dough products made at the Danville factory this month after the FDA told Nestle it suspected that consumers may have been exposed to E. coli bacteria after eating the dough raw.

The FDA and the federal Centers for Disease Control and Prevention have been investigating whether the cookie dough was the source of the E. coli outbreak which has sickened 69 people in 29 states, according to the latest CDC data.

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

The FDA says the sample of Toll House refrigerated prepackaged dough was manufactured at the plant on Feb. 10.

In a statement, Nestle said the sample that tested positive came from a 16-ounce Toll House refrigerated chocolate-chip-cookie-dough bar. The product had a "best before June 10 2009" label.

"We are very concerned about those who have become ill . . . and deeply regret that this has occurred," the company said in the statement.

The company also reiterated that consumers can return the recalled products to their local grocer for a full refund.

FDA spokeswoman Stephanie Kwisnek says the FDA is working with the Glendale, Calif.-based unit of Switzerland-based Nestle SA to find the source of the contamination.

Nestle said it will continue to work "closely and in full cooperation" with the investigation.

In addition to the Toll House products, Nestle also makes a variety of refrigerated pastas and pasta sauces at the plant.

The company shut down production in the cookie-dough section of the plant when it issued the recall.

That section remains closed, but the company is still manufacturing the pasta and pasta sauces in a separate section of the plant.