South Korean couple vandalise painting worth $500,000 by 'mistake'

A young couple accidentally vandalised a painting worth about $500,000 at a gallery in Seoul, its exhibition head said on Friday.

CCTV footage showed the couple using acrylic paint and a brush that were part of a display near the artwork to splatter a new addition to the piece, which is one of about 130 at the 'Street Noise' exhibition at Lotte World Mall.

Gallery staff called police after discovering the new dark green-coloured marks on Sunday afternoon at 14:10 local time (0510GMT), about 30 minutes after the couple left the area, the organizer said.

Police accessed the CCTV footage, secured the paint pot and brush to take fingerprints and tracked down the couple in the shopping mall where the gallery is located.

"They confessed that they thought they were allowed to do that (as participatory art) and made a mistake," exhibition head Kang Wook said. "We are in discussion with the artist to decide what to do."

The 240cm by 700cm sized 'untitled' graffiti artwork made by Jon One in 2016 as a live painting performance in front of an audience in Seoul is worth about $500,000, Kang added.

The gallery has since put a black wire barrier around the display and additional "Do Not Touch" signs explaining that the paint pots and brushes are part of the artwork.

Some visitors were seen taking pictures in front of the damaged artwork on Friday morning, and the exhibition organizer said the incident has generated increased interest in the show.

"After seeing the news report, I was curious, so I came earlier than planned. Damaging original artwork is a serious wrongdoing. I think it should be restored," visitor Lee Seon-mi said at the gallery.