Some Costco customers are crying fowl over the big-box chain’s popular $4.99 rotisserie chickens, saying they contain preservatives in spite of the company’s claims to the contrary, according to a new lawsuit. The class-action lawsuit, filed last week in San Diego federal court, alleges that Costco makes the claim despite the fact that the rotisserie chickens contain sodium phosphate and carrageenan. 3 A class-action lawsuit alleges that Costco falsely claims that its rotisserie chickens are free of preservatives. 3 A Costco spokesperson said that the company has “removed statements concerning preservatives from the signs and on-line presentations” for its rotisserie chickens. Costco’s rotisserie chicken is wildly popoular.