Korean burger chain Lotteria is facing criticism over alleged hygiene issues, after an employee appeared to reuse a hamburger bun that they had dropped on the floor.

After visiting a Lotteria branch in Changwon, South Gyeongsang Province, a customer filed a complaint that while watching an employee make the burger, the mayonnaise-slathered side of a bun fell to the floor. The complaint alleges the employee picked the bun back up and served it to the customer.

According to the customer, the employee said the bun that fell on the floor had been thrown out. However, when the customer checked the trash can, no bun was found. It was only then that the employee apologized and agreed to remake the burger.

The customer also reported the matter to the Ministry of Food and Drug Safety and confirmed the events through security camera footage in the store.

Local authorities conducted an on-site inspection and confirmed the details of the customer’s complaint after talking with the branch manager. They additionally imposed a fine of 1.5 million won ($1,160) after discovering unhygienic cooking utensils.

“We will continuously train all staff members in our branches to make sure it doesn't happen again," an official of Lotte GRS, which operates Lotteria, told The Korea Herald. The employee in question has reportedly been removed from the position.

Meanwhile, on April 12 a Lotteria branch in Gyeonggi Province was suspended for five days after a live cockroach was found inside a customer’s drink.