Nestle USA’s flour supplier for its Danville, VA cookie dough plant is now the focus of a joint investigation by the U.S. Food and Drug Administration (FDA) and the Virginia Department of Agriculture and Consumer Services.

The name of the flour supplier was not made available.

FDA found the E. coli O157:H7 bacteria in samples of the prepackaged Nestle Tool House refrigerated cookie dough, but inspections inside the Danville plant found no traces on equipment or workers.

As result, FDA is turning to individual ingredients beginning with the flour in hopes of finding out how a deadly bacterium from the intestines of cattle came to be found in raw cookie dough.

The contaminated Nestle cookie dough is now blamed for infecting 72 people in 30 states with a strain of E. coli O157:H7 with a common DNA fingerprint. Fifty-one have been confirmed by advanced testing and additional confirmatory tests results are pending on the others.

The E. coli outbreak forced Nestle to recall an estimated 300,000 cases of the popular Toll House cookie dough, or 3.6 million individual packages.

The victims range in age from 2 to 65 years old. Most (71 percent) are female, and 65 percent are under 19 years of age. While no deaths have yet been attributed to the outbreak, 34 have been hospitalized and ten have developed the often life-threatening hemolytic uremic syndrome (HUS).

The number of infections is also continuing to rise.

Food safety attorney Bill Marler, managing partner of the Seattle law firm of Marler Clark, is urging Nestle to immediately begin paying the medical bills and lost wage claims of all legitimate victims of the outbreak. Marler has already sued Nestle on behave of victims in Colorado, California and Washington State.

“True, it will not completely prevent Nestle from being sued to both uncover why the outbreak happened and to deal with the suffering of the victims and the need for possible future medical expenses that might well include life time monitoring, kidney dialysis and transplant, but it certainly will not hurt, “ says Marler.