K-pop fans, including those from China and Japan, were denied entry to the popular year-end televised music festival, SBS Gayo Daejeon, on Christmas after falling victim to a ticket scam.

Fans who had purchased tickets from secondhand online markets discovered too late that the tickets were fake, rendering them unable to enter the Inspire Arena in Yeongjong Island, Incheon, where the SBS Gayo Daejeon took place at 5 p.m. on Monday.

The festival attracted a massive crowd, featuring a lineup of hit K-pop groups, including IVE, NewJeans, ITZY, (G)I-DLE and TVXQ.

"I never imagined that I would be denied entry even with the actual ticket in my hand," a 20-year-old who preferred not to be identified told the JoongAng Ilbo, an affiliate of the Korea JoongAng Daily.

"I traveled all the way to Seoul around Dec. 15 and bought the ticket from a person I met through Bungaejangter [an secondhand online market]," the fan said. "I was given the impression that the tickets were distributed by an agency commissioned to organize the event. It turned out that the person who sold the ticket was a part-timer" working for a fraud company.

The fan spent a total of 1.7 million won ($1,300) to buy four tickets — 400,000 won each, plus 100,000 won for the cab fare for the person who sold the ticket.

The arena where the music festival took place turned into chaos as many other people discovered their tickets were fake.

Some attendees with genuine tickets found themselves in a situation where others with fake tickets had occupied their seats.

Those who were denied after unknowingly presenting fake tickets were furious, saying that their Christmas had been ruined.

The arena was overcrowded as more people showed up than the original 10,000 seats that were sold.

Some individuals shared tips online on how to check whether a ticket is fake using UV lamps sold at Daiso.

On Monday, the Korean broadcasting station, SBS, issued a statement acknowledging the sale of fake tickets and announced it would request a police investigation.

Most of the tickets for the music festival were reserved for foreign attendees. Official fan clubs of each K-pop group were allocated only 90 seats.

The number of free tickets provided to agencies participating in the festival was reportedly less than 300.

While free tickets were randomly distributed to people who participated in a pre-registration event, the total number of tickets to be sold in Korea was limited to 5,000.

Some speculate that the ticket scams were orchestrated by an organized group.

A 20-year-old who unwittingly sold fake tickets online told the JoongAng Ilbo that he, too, was a victim of a scam.

"I saw a part-time job offering posted on Albamon on Dec. 4 from a company called Galaxy," the 20-year-old, who preferred not to be identified, said. "After exchanging texts with an employee at the company, I received the tickets near the office in Gangnam."

He said he was told that the tickets that he received were actually not for sale, but he would receive a 5 percent commission on each ticket sold.

"I was able to contact the employee up until Christmas Eve," the 20-year-old said. "However, all connections were cut off on Christmas morning."

So far, the individual claimed to have sold around 40 to 50 tickets.

Around 90 victims who purchased the fake tickets joined a group chat on KakaoTalk.

"It seems that the company had hired other part-timers," the 20-year-old told the JoongAng Ilbo. "It seemed that they had also tried to sell tickets to other broadcasting stations' year-end parties up until the last day of the year."

The 20-year-old extended their apologies to the victims of the scam and pledged to cooperate with investigators.

The issue of fake tickets at year-end festivals has become a major concern.

In a previous incident, the police apprehended several individuals who had sold 200 million won worth of fake tickets to the singer Lim Young-woong's concerts held between April last year and July this year, with ticket transactions taking place via social media.

BY SHIN HYE-YEON [shin.hyeyeon@joongang.co.kr]