Costco's Kirkland Signature items traced to external manufacturers

Investigations have revealed that Costco’s Kirkland Signature golf balls are produced by South Korean manufacturer Nassau Golf, despite the retail brand’s secrecy about its suppliers. In a separate probe, the source of Kirkland canned tuna appears to be major U.S. tuna processors such as Bumble Bee Foods, Starkist and Chicken of the Sea, with labeling clues pointing to these companies. Costco keeps the identities of its private‑label partners undisclosed to protect its brand image and maintain low prices for members.

These findings illustrate the broader practice of large retailers outsourcing production to established manufacturers while marketing the goods under their own private‑label names.