McDonald's Korea has suspended sales of its limited-edition Chungju Corn Cheese Croquette Burger after receiving multiple customer complaints that small stones were found in the product, cutting short a promotional campaign that had become one of its fastest-selling seasonal menu items.

The company halted sales of the latest menu item in its Taste of Korea campaign on Thursday, nearly two weeks before its scheduled end on Aug. 12.

"There were complaints that customers bit into stones, and this is an issue related to safety," a McDonald's Korea official said. "So, considering customer safety, McDonald's took the preemptive measure of ending sales early."

The burger, launched on July 9 as the sixth menu item under the fast-food company’s Taste of Korea campaign, surpassed 1 million units in sales within two weeks of its release.

Launched to mark the fifth anniversary of the campaign, the burger featured a mozzarella cheese croquette made with waxy corn from Chungju, North Chungcheong Province.

McDonald's Korea said the menu was created in collaboration with Chungju and used about 25 metric tons of locally produced corn to support regional farmers.

The campaign, launched in 2021, develops menu items using Korean agricultural specialties to promote local produce and expand sales channels for regional farming communities.

The company has halted sales after receiving at least three complaints from customers who reported finding stones in the burger, as its internal guidelines call for a sales suspension when three or more cases involving the same safety concern are reported.

It is currently investigating how the stones entered the product with its raw material suppliers and other partners involved in the production process.

The official added that the product's sales had been terminated permanently.

“The sales ended completely ahead of schedule, so I don’t think the company will resume them even after the cause is identified,” the official said.

The burger took about a year to develop, going through concept planning, ingredient selection, prototype production and consumer testing before its launch.

Meanwhile, McDonald's Korea has been expanding its Taste of Korea lineup overseas, with its Changnyeong Garlic Burger becoming the first item from the campaign to enter a foreign market.

The burgers were launched at McDonald's Taiwan last month in beef and chicken versions, using garlic sauce made from Changnyeong-grown garlic supplied through Korean food manufacturer Ottogi.