The government of Sudan is angry that a cancer-causing dye at the centre of a food scare in the UK is named after the north African country.
Tests on rats have shown the dye can cause bladder and liver cancer
Sudan's ambassador has written to the Food Standards Agency, asking it to change the name of Sudan 1 to prevent further harm to Sudan's reputation.
Hundreds of products were withdrawn from UK supermarkets after the illegal dye was used to brighten chilli powder.
Sudan's government is accused of war crimes in the western Darfur region.
'Not a good thing'
Hassan Faraj, Sudan's deputy ambassador in the UK, said the name of the dye was causing problems for his country.
"We are unhappy because the name of this strange material is associated with our country, and it is known as cancerous and this is not a good thing for the name of our country," he told the BBC's Network Africa programme.
"We have officially written to the FSA and we are waiting for their reply. We are eager to know and my government is also eager to know why it is called Sudan 1."
He said the Sudanese government had asked the FSA to re-name the dye, and to publicise the new name "in all the major papers here that the country known as Sudan has nothing to do with it".
The name is "not a small thing" said Mr Faraj, because Sudan exports foodstuff to Europe and the Middle East, and not changing the name "will have damaging or catastrophic effects on our exports".
The FSA says it plans to respond to Sudan's letter in the coming days, although it will not comment on what action it might take.
The FSA says it does not know the genesis of the name of the dye, but it is researching its origins.
Prof John Griffiths, who teaches functional dye chemistry at Leeds university in the UK, says the dye - also known as 1-phenylazo-2-naphthalenol - probably got the name as a result of interest in the British Empire at the time it was developed in the late 19th Century.
"Manufacturers have a free hand to call them whatever they want, so they would choose names that were visibly exotic or related to what was topical at the time," he said.
There are Congo reds and Congo browns, he says, which along with Sudan colours "would be a relatively fiery colour, suggestive of hot countries".
"We wouldn't have a Sudan cream, it is going to be Sudan orange or Sudan red."