Young couple mistakenly vandalizes $440,000 painting in South Korea

The work was done in 2016 by American graffiti artist JonOne.

Staff at the gallery exhibition noticed new brush strokes on the wall -- small swipes of dark green to the right of center -- last Sunday. After checking the security camera, two suspects were taken by the police for investigation.

The agency that organized the exhibition told ABC News that it is currently negotiating with the artist to take appropriate steps.

"We called the police immediately and talked to the insurance company for the damaged artwork," Kang Wook, the CEO of Contents Creator of Culture, co-organizer of the exhibition, told ABC News. "But as the agency in charge, we will do best to minimize the harm to the couple who unintentionally vandalized the work."

According to Kang, the graffiti was not framed due to its large size. The vandalized art was 22.9 feet by 7.8 feet, and was the only piece in the exhibition without frames.

“Given the circumstances, the young couple does not seem to have done it intentionally.” John Andrew Perello, who goes by the name JonOne, told ABC News. “I hope the piece gets restored to meet the Korean audience like before.”

The damaged art piece by JonOne is worth around $440,000, according to its agency. The graffiti "Untitled," which attracted even more public attention in South Korea after it was painted on, will hang until June 13, at the Street Noise exhibition at the Seoul-based Lotte World Mall.

The decision to display performance equipment in front of JonOne's work goes back to 2016. JonOne completed the artwork in question during a graffiti museum show, "The Great Graffiti,'' in Seoul Arts Center at the time. When the piece was complete, it was displayed along with the props used by the artist, in the same way the display is on now.

"The paint and brushes used by the artist comprise a complete set with the graffiti canvas work," said Kang. He explained that the props were part of the exhibition to help highlight the history of the artist's work.

Since the accidental painting, the agency in charge of the exhibition has provided additional guidelines for spectators and increased the surveillance around the work to prevent such misunderstandings from taking place again.

"Due to the characteristics of contemporary art, there will be many happenings like these going forward. Exhibit organizers must take extra care in physically protecting the artwork, as the audience may mistake the art like that of JonOne's to something they can scribble on," Ha Jae-geun, a Korean pop culture expert, told ABC News.

JonOne, who now lives in Paris, received France's Legion of Honor in the culture and communications category in 2015. France's premier award goes to those recognized for their service to the country.

ABC News' Hakyung Kate Lee contributed to this report.