The FBI executed search warrants at both the plant in Blakely, Ga., and at Peanut Corp. of America's headquarters in Lynchburg, Va., according to a senior congressional aide with knowledge of the raids. The official spoke only on condition of anonymity because he was not authorized to speak publicly on the matter.
The plant has been identified as the source of the salmonella that has sickened hundreds and killed as many as eight people.
Atlanta television station WSB's cameras captured FBI agents entering the plant and leaving with boxes and other material.
Earlier Monday, Agent Gregory Jones in Atlanta said the FBI had joined the investigation into the outbreak. The FBI didn't immediately return a message left seeking further comment on the raid Monday night.
The House Energy and Commerce investigations subcommittee, which also is investigating how tainted peanuts got into the food supply, has scheduled a hearing for Wednesday. The subcommittee, chaired by Rep. Bart Stupak, D-Mich., has called a meeting on Tuesday to issue a subpoena for company president Stewart Parnell, who has indicated he will not otherwise appear at Wednesday's hearing, the congressional source said.
Monday's searches come three days after Food and Drug Administration investigators said Peanut Corp. knowingly shipped salmonella-laced products from its Georgia plant after tests showed the products were contaminated. Federal law forbids producing or shipping foods under conditions that could make it harmful to consumers' health.
The Justice Department has opened a criminal investigation and more than 1,550 products have been recalled.