SEOUL, KOREA: South Korea's food watchdog said Friday (16 May) that metal pieces found in the patty of a McDonalds' hamburger early this month came from a cooking utensil at the food giant's flagship store here.

The Korea food and drug administration (KFDA) said its officials will inspect the store in central Seoul at some point in the future to prevent the incident from reoccurring.

"Should the incident reoccur, the store could face a suspension of operations for one week," a KFDA official said.

Food inspectors investigated allegations raised by a customer, identified by her surname Song, that she found metal fragments in the patty of a Big Mac at the store while eating burgers with her family.

Nine tiny metal pieces, 1 to 5 millimetres each, were scattered in the patty, according to the KFDA.

The metals came from a spatula, a kitchen utensil used to lift, move and flip patties, the KFDA said. Employees were required to sharpen the edge of spatulas five or six times a day and subsequently wash the utensil to separate blade fragments. But a crew member of the flagship store did not follow the manual, the KFDA said.

McDonalds said it has decided to replace the current spatula with a disposable one. "We agree with the results of the probe," a spokesperson of McDonalds said.

The finding comes amid a public scare over food safety following the discovery of a mouse head in one of the country's most popular snacks, Saewookkang, made by Nongshim, and a knife blade in a can of tuna, made by Dongwon F&B.

In Korea, McDonalds is the second-largest fast-food chain behind Lotteria. (By JIN HYUN-JOO/ The Korea Herald/ ANN)