Texas has ordered a recall of all products ever shipped from a now-closed Peanut Corp. of America plant in Plainview amid a nationwide salmonella outbreak.

The order came Thursday evening from the Department of State Health Services. The agency says "dead rodents, rodent excrement and bird feathers" were discovered Wednesday in a crawl space above a production area.

A state inspection also found that the unit's air handling system was pulling debris from the infested crawl space into production areas.

The plant began operating in March 2005 but was shut down earlier this week.

The health department order also requires the plant to stop producing and distributing food products. Peanut Corp. of America is at the centre of a salmonella outbreak investigation.

The outbreak has sickened some 600 people in the U.S. and may be linked to nine deaths — the latest reported in Ohio on Wednesday — and has resulted in one of the largest-ever product recalls. A Canadian who purchased a product in the U.S. was among those who fell ill.

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.