(CNN) -- Tests show products at a Peanut Corporation of America subsidiary in Texas may be tainted with salmonella, state health authorities said on Tuesday.
The Texas Department of State Health Services said on Tuesday it requested that the plant be closed after the company reported the findings of a private lab.
Doug McBride, a health services spokesman, said the positive samples were taken last week and the private company's lab results came back on Monday. State test results were expected to come back on Tuesday.
The company voluntarily closed its Plainview, Texas, plant on Monday night "after laboratory tests of sample products from the plant indicated the possible presence of salmonella in some products," state health officials said.
A Blakely, Georgia, peanut processing plant is under investigation in connection with a salmonella outbreak that has been linked to eight deaths and has sickened about 600 people nationwide. That facility is not operating at this time, the FDA said on Tuesday.
Operations of the Plainview Peanut Co. have been halted while state investigators and the FDA "complete their investigation of the plant's procedures and records of food safety."
The state health agency said it is unaware of any illnesses linked to Plainview products and "is developing specific criteria the company must meet before it can resume production."
"The peanut meal and granulated peanuts had not been shipped out of the Plainview facility. The dry roasted peanuts had been shipped to a distributor but were detained and recalled before further distribution. It is not yet known if the salmonella possibly found in the product testing is the same strain of the bacterium implicated in a 43-state outbreak of salmonellosis," Texas authorities said.
The Peanut Corporation of America, which runs the processing plant, said on its Web site on Tuesday that the Plainview plant is making the move voluntarily to cooperate with authorities.
The original peanut butter recall launched weeks ago has expanded to include more than 1,000 products.
The Peanut Corporation of America originally said tainted peanut butter and peanut paste were shipped by Peanut Corporation of America to institutions such as schools, nursing homes and prisons but not grocery stores.
But on Sunday, the company revised its recall notice to say products were in fact sold to some retail outlets, dollar stores, such as 99 Cent Stuff, 99 Cents Only Stores, Dollar General, and Dollar Tree Stores. Products include Casey's, Parnell's Pride, Reggie, and Robinson Crusoe labels.
Companies that make peanut butter are reporting a dip in sales despite the FDA's assurances that major-label peanut butter in grocery stores is safe. See FDA's list of recalled peanut products.
Peanut butter makers not affected by the deadly salmonella outbreak are trying to get consumers to keep buying peanut butter. Companies such as ConAgra Foods Incorporated and J.M. Smucker Company have been running ads and offering coupons, trying to lure peanut butter customers as sales have plunged at least 20 percent since the salmonella outbreak.
The Blakely plant was raided by the FBI Monday morning, a CNN affiliate reported.