(CNN) -- Dominican authorities have warned consumers not to eat a brand of sugar imported from Brazil after tests found that it was tainted.
The sugar came from a 14,000-metric-ton shipment that has been on the market since July and is "not suitable for domestic consumption," the Dominican Republic's consumer protection agency said.
The Canaria brand sugar was imported from Brazil by the Casa Chepe company, the agency said in a statement posted on its Facebook page Sunday. Representatives from the company could not be immediately reached for comment.
The Dominican Republic's health ministry has ordered a recall of the refined white sugar, and the local company agreed to pull it from shelves, the consumer agency said.
The importer has reported that supermarkets have already started returning 2- and 5-pound bags of the sugar, the agency said.
An investigation was under way to determine who produced it, authorities said.
The agency said it received 15 complaints about the sugar in August, alleging that it had been mixed with sand.
Two tests analyzing the sugar found that it contained "an insoluble material composed of silicon dioxide, calcium carbonate and cellulose fibers," the agency said, noting that silicon dioxide is one of the components of sand.
The compound is also a food additive that can be used to prevent caking, according to the U.S. Food and Drug Administration.
CNN's Catherine E. Shoichet and journalist Diulka Perez contributed to this report.