A couple in South Korea accused of damaging a precious artwork by a famous US artist have told the head of the exhibition that they thought they had been invited to do so.

The untitled piece by graffiti artist JonOne, estimated to be worth as much as $US500,000 ($657,000), was on display at a gallery at the Lotte World Mall in Seoul.

It had been painted in 2016 in front of an audience in the South Korean capital.

Paint cans and brushes from the live performance are moved with the piece and are displayed on the ground in front of the painting and considered part of the artwork.

According to exhibition staff, CCTV cameras captured a young man and woman picking up some of the paint and splattering and rubbing it on the artwork.

The 240cm by 700cm untitled #artwork is estimated to be worth as much as $500,000 and was painted by #JonOne in 2016 in front of an audience at #Seoul's Lotte World Mall.https://t.co/mhX2bO0YLH

— The Peninsula Qatar (@PeninsulaQatar) April 2, 2021

Police reviewed the security video before arresting the couple at the mall.

They were later released, said the head of exhibition, Kang Wook, adding that the gallery had decided not to file charges because it appeared to be an honest error.

“They thought they were allowed to do that as participatory art and made a mistake,” Mr Kang said.

“We are currently in discussions with the artist about whether to restore it.”

After the incident, the gallery put up a wire fence and additional signs saying: “Do Not Touch”.

Some visitors were seen taking pictures of the damaged artwork over the weekend.

Mr Kang said that inquiries about the show had increased after the incident.

-Reuters/ABC