An independent watchdog agency has uncovered flaws in a crucial part of the nation's rapid-response plan — the ability to trace food to the company it came from during an illness outbreak or bioterrorism attack.

Federal auditors found that nearly half of all the food manufacturers they surveyed that are supposed to register with the Food and Drug Administration failed to give the agency accurate contact information.

Congress set up the program after the Sept. 11 attacks to keep food safe from bioterrorism and to allow quick tracebacks when contaminated food reaches consumers.

The Office of Inspector General of the Health and Human Services Department warns that the FDA needs to improve its record keeping and consider fining violators.