An off-the-cuff remark by David Cameron at the Arts Council last week appears to have caused a storm in Lithuania.
The Tories say Mr Cameron meant no offence
The Tory leader's comment that he hoped no grants were given to "one-legged Lithuanian dance troupes" has hit the headlines in the Baltic state.
Ambassador Vygaudas Usackas wrote to Mr Cameron saying it had caused "great concern" in his homeland.
The Tories said he had been referring to concerns that grants ended up with unusual causes and meant no offence.
The remark was reported in the Mail On Sunday last week, which said Mr Cameron had been overheard referring to "one-legged Lithuanian lesbians".
Mr Cameron's office later said that was not correct and he had referred to "one-legged Lithuanian dance troupes", to make a serious point about Lottery grants.
The story has been picked up by Lithuanian newspaper Lietuvos Rytas, and prompted a letter from the Lithuania's ambassador, Mr Usackas.
He wrote: "It would be incredibly helpful to understand exactly what you meant when referring to 'Lithuanians' and how this relates, if at all, to the Arts Council.
He added: "This will enable me to pass your message to the many Lithuanians living in the UK and also to their homeland, where this report has caused a great deal of concern."
A party spokeswoman said that Mr Cameron had plucked the word "Lithuanian" from the air and had not intended to make a comment about the country or its people.
He was making a point about the perception that grants can end up going to unusual causes, she said.
"We have had a dialogue with the ambassador last night, and we just wanted to stress that absolutely no offence was meant in David's comment," she said.
"It's not in any way a slight to Lithuania, with which we have very friendly relations."