In this Jan. 29, 2009, photo, an Early County, Ga., sheriff's car sits parked in front of the Peanut Corporation of America processing plant in Blakely, Ga. The plant is being blamed for the salmonella outbreak that has sickened at least 550 people, eight of whom have died. (Ric Feld/Associated Press)

U.S. federal agents on Monday raided a Georgia peanut processing plant linked to a countrywide salmonella outbreak, hauling away boxes and other material.

A senior congressional aide with knowledge of the raids said the FBI executed search warrants Monday at both the plant, in Blakely, Ga., and at Peanut Corp. of America's headquarters in Lynchburg, Va.

The official spoke only on condition of anonymity because he was not authorized to speak publicly on the matter.

An Atlanta television station captured FBI agents entering the facility and leaving with the boxes.

The FBI didn't immediately return a message seeking comment on the raids.

The salmonella outbreak, which occurred between Sept. 3 and Dec. 29, has sickened 575 people in the U.S. and might have caused as many as eight deaths; no illnesses or deaths have been reported in Canada.

The U.S. government has opened a criminal investigation, officials said. U.S. federal law forbids producing or shipping foods under conditions that could make it harmful to consumers' health. The company has denied any wrongdoing.

More than 1,550 products containing peanuts, ground peanuts, peanut paste or peanut butter from the firm's Georgia plant have been recalled in the U.S., while the Canadian Food Inspection Agency has recalled about 170 items.