A peanut processing plant in Texas run by the same company blamed for a national salmonella outbreak operated for years uninspected and unlicensed by government health officials, The Associated Press has learned.

The Peanut Corp. of America plant in Plainview never was inspected until after the company fell under investigation by the U.S. Food and Drug Administration, according to Texas health records obtained by AP.

Once inspectors learned about the Texas plant, they found no sign of salmonella there. But new details about that plant including how it could have operated unlicensed for nearly four years raise questions about the adequacy of government efforts to keep the nation's food supply safe. Texas is among states where the FDA relies on state inspectors to oversee food safety.