The Ivy Chelsea Garden has blamed "confusion" over its dress code for an allegation of racism, after singer Raye claimed her friend wasn't allowed into the restaurant because he was black.
The singer posted a video on Instagram, showing an altercation between her and a member of staff at the restaurant.
The restaurant later described allowing one member of Raye's party in before barring her black friend from entering as a "mistake".
"We're not coming to the Ivy again, it's disgusting, it's absolutely disgusting. It's racist," the singer can be heard to say in the video.
She also posted an email from an Ivy Collection spokesperson which said: "A member of a party was not thought to be dressed appropriately and this was explained to them.
"This has absolutely nothing to do with racism and we completely refute these allegations."
Describing herself as "upset beyond words", Raye later told BBC's Newsbeat: "If your laws and rules are smart casual then you enforce that on everybody, white and black. You don't pick and choose."
At the time of the accusation the restaurant's website said it had no dress code "but our guests generally are smart casual".
The website has since been updated to say that the dress code is smart casual.
In a statement on Instagram, the restaurant said: "There was a situation yesterday during which a gentleman was refused entry because he was wearing non-smart casual clothing.
"Unfortunately, a mistake had been made and another member of his party had earlier been allowed in wearing similar clothing.
"The dress code for our restaurant is smart casual. We are sorry that this was not made clear on our website and other channels and this ambiguity has now been rectified.
"The Ivy Chelsea Garden takes all allegations of racism extremely seriously and we will make sure that our dress code is explained to all guests so that this confusion does not happen again."