An American ice cream maker has launched a brand that evokes the British militia that terrorised the Irish during the 1920s.
Ben and Jerry's began promoting its Black and Tan flavour - cream stout with a whirl of chocolate - this month, but said it was unaware of the connotations that the name has in Ireland.
The company, whose mission statement promotes "deep respect" for individuals, has apologised for any offence their latest product has caused to the Irish.
The Black and Tan ice cream is based on the alcoholic drink of the same name, which is made by mixing stout with pale ale.
But the phrase originates from the 8,000 ex-servicemen who went to Ireland to keep order as Britain attempted to control republican rebels.
The Black and Tans were recruited to support the Royal Irish Constabulary and their name came from the mixture of police uniforms and khaki that they wore.
In November 1920 they massacred 12 people at a Gaelic football match in Croke Park, Dublin. The killings were in response to the IRA murdering 14 undercover detectives.
Yesterday Michael Laffan, the head of history at University College Dublin, said: "The very name Black and Tan still has a resonance.
"This is something that would provoke a response and make hackles rise in some quarters, because they were a nasty group. They did carry out a lot of killings."
The ice cream is available in the United States but has yet to be launched internationally.
A spokesman for the Vermont-based ice cream maker, which is owned by Unilever, said: "We have had a small amount of contact from people letting us know how Black and Tan originated. We were not aware of that.
"It was named because it's a very popular drink in the US. It was released in the United States before being promoted for international use. That's now being discussed."