Krispy Kreme has apologised "unreservedly" after a branch in Hull mistakenly named a half-term promotion "KKK Wednesday".
The doughnut chain outlet in question used social media to advertise its Wednesday promotion as the Krispy Kreme Klub, without realising the direct connotation to the racist white supremacist group Ku Klux Klan.
It was advertised as part of a calendar of events to keep children entertained during the holiday via its Facebook page, which has more than 200,000 followers.
"Krispy Kreme apologises unreservedly for the inappropriate name of a customer promotion at one of our stores," a company spokeswoman said.
"This promotion was never intended to cause offence. All material has been withdrawn and an internal investigation is currently underway."
The KKK, known for its white robes and conical hats, started its violent campaign against African Americans in the 19th and 20th century. In recent times it has rebranded its image to include people of Jewish and Hispanic origin as well as homosexuals.
The Klan is estimated to have between 5,000 and 8,000 members according to figures released in 2012.