The Paris Musée d'Orsay, home to some of the world's most famous nude paintings, has been criticised for refusing to let a woman in a low-cut dress enter.
French literature student Jeanne visited the museum on a hot Tuesday afternoon, but museum staff barred her from entering until she agreed to cover up her cleavage.
"Oh no, that's not going to be possible, that's not allowed, that is not acceptable," she quoted the ticket agent saying.
Three other members of the staff, including a security guard, told her what she was wearing - a dress with a plunging neckline - was against the museum's rules.
In an open letter shared on Twitter, Jeanne said the museum officials were staring at her breasts as they demanded she put her jacket on before entering the museum.
"I don't want to put on my jacket as I feel beaten, compelled, I'm ashamed. I feel everyone's looking at my breasts. All I am is breasts; all I am is a woman they are sexualising," she wrote.
Her open letter went viral on social media and the Musée d'Orsay contacted her to apologise.
"We learned of an incident that occurred with a visitor when she entered the Musée d'Orsay. We deeply regret this and apologise to the affected person we contact," it tweeted.
Jeanne told the BBC the museum provided her with a very sincere apology but its response on Twitter "failed to recognise the sexist and discriminatory nature of the event".