CHICAGO – Concern over salmonella contamination has prompted an Illinois firm to recall nearly 40,000 pounds of a dietary ingredient, a move that in turn prompted several recalls of supplements containing the suspect material.

U.S. Food and Drug Administration officials said they are investigating whether the ingredient, sold by Westchester-based Ingredion and made in a subsidiary’s plant in South Korea, wound up in other dietary supplements sold to consumers and whether more recalls are necessary.

The recalls began in May after Ingredion discovered that several lots of galactooligosaccharides tested positive for salmonella, bacteria that can cause serious and even fatal illness.