Yesterday, the Joan Mitchell Foundation (JMF) sent Louis Vuitton a cease-and-desist letter, alleging that the French luxury brand committed copyright infringement when it featured the late Abstract Expressionist’s paintings in the background of advertisements for the brand’s Capucines handbags.

The JMF is staunchly against the use of Mitchell’s artworks for commercial purposes. Their letter demands that the brand withdraw the campaign within three days or face further legal action, according to a report in the New York Times.

The foundation acknowledged that Louis Vuitton initially reached out to seek permission to use the imagery in the campaign. But after the request was refused the brand went ahead anyway, claimed the foundation. The ad ran online and in newspapers, featuring actress Léa Seydoux with the bag in front of three of Mitchell’s paintings.

“As an artist-endowed foundation dedicated to stewarding Mitchell’s work and legacy, JMF carefully manages how images of the artist’s work are used in accordance with its mission,” said the Joan Mitchell Foundation in a public statement. “It is a grave disappointment to JMF that Louis Vuitton has such disregard for the rights of an artist and would exploit her work for financial gain.”

The works in question—La Grande Vallée XIV (For a Little While) (1983), Quatuor II for Betsy Jolas (1976), and Edrita Fried (1981)—are currently on display in the exhibition “Monet-Mitchell” at the Fondation Louis Vuitton in Paris.

Joan Mitchell, Edrita Fried (1981). Collection Joan Mitchell Foundation. © Estate of Joan Mitchell.

Christa Blatchford, director of the JMF, told the Times that Bernard Arnault, the billionaire chief executive of LVMH, which owns Louis Vuitton, offered to make a donation to the JMF in return for permission to feature Mitchell’s works in the ad campaign.

The JMF confirmed to Artnet News that it also sent a cease-and-desist letter to the Fondation Louis Vuitton for violating a license agreement that prevents the reproduction of Mitchell’s works from the exhibition without consent.

“This whole experience has made it clear to us that the separation we thought was in existence between the Fondation Louis Vuitton and the company was not there,” said Blatchford.

Artnet News has reached out to Louis Vuitton for comment but has not heard back by the time of publication.

Louis Vuitton recently made headlines for its collaboration with Yayoi Kusama, featuring polka dots and even a robot lookalike of the Japanese artist. The brand first partnered with Kusama in 2012 under the helm of Marc Jacobs.