A passenger jet from Korean Air / Courtesy of Korean Air

Korean Air is mired in yet another scandal on its lax security checks, after one of its flight attendants was caught carrying ammunition with her while boarding a flight from Incheon to Bangkok, according to the police, Thursday.

A female employee attempted to board the flight with live ammunition in her pouch bag, Tuesday, but was stopped by a security official at Incheon International Airport during luggage scanning.

An internal investigation by Korean Air showed that she did not intend to pose any security threat. The airline said the flight attendant brought the old bag she had used at an early age and was not even aware that there was a bullet in it. She picked it up in the street in her childhood and kept it in the bag, according to police investigation.

But this sparked calls for the nation's flag carrier to heighten its vigilance on security checks, as the airline was involved in a series of similar controversies in recent years.

A bullet was found underneath a seat on a flight from Incheon to Milan, Italy, on March 24. It was spotted during pre-flight cabin cleaning.

The airline also came under severe criticism for its poor safety monitoring in March 2023 when an American passenger brought with him two bullets on a flight from Incheon to Manila. The passenger jet from Korean Air ended up returning to the terminal shortly before takeoff.

At that time, a total of 230 passengers and cabin crew evacuated the airplane. All of them went through extra security checks, and the flight was delayed for about four hours.

The airline pledged to strengthen security monitoring and education to prevent further security scandals.

"We will actively cooperate with the investigation from police and relevant authorities," an official from Korean Air said. "Korean Air conducts security education online and offline regularly for all flight attendants. We will further reinforce education and raise their sense of security."

Police allowed the employee to board the flight after taking away the bullet. She will be investigated further upon returning to Seoul.

According to data compiled from Rep. Jeong Dong-man of the ruling People Power Party, a total of 1,439 life-threatening products, such as guns, ammunition and knives, were found during security checks from local airports between 2019 and September 2023. This has raised calls to recruit more security personnel and develop their training systems at the airport.