The fast-food chain announced on Aug. 2 that it had halted nationwide sales of the Chungju corn cheese croquette burger at 8 p.m. on July 30, nearly two weeks before its scheduled end on Aug. 12, The Korea Herald reported.

The burger, introduced on July 9, features a deep-fried cheese croquette packed with glutinous corn kernels sourced from Chungju in North Chungcheong Province.

"There were complaints that customers bit into stones, and this is an issue related to safety," a McDonald's Korea official said as quoted by The Korea Times.

"So, considering customer safety, McDonald's took the pre-emptive measure of ending sales early."

A Chungju sticky corn cheese croquette burger. Photo courtesy of McDonald's Korea

A McDonald's Korea spokesperson said the company suspended sales after receiving at least three similar complaints, in line with its internal safety policy.

The company said it is investigating how the stones entered the product with its raw material suppliers and other partners involved in the production process.

It does not plan to reintroduce the burger.

Since its debut, more than one million servings of the burger has been sold.