A claim that milk from the offspring of a cloned cow was on sale for public consumption is to be investigated by food safety officials in Britain.
The disclosure has provoked concern among some farming campaigners, and the Food Standards Agency (FSA) is set to investigate a report in Friday's International Herald Tribune newspaper.
But the body that represents Britain's dairy industry insisted that there was no danger.
The newspaper quoted a British dairy farmer, speaking anonymously, saying that he was using milk from a cow bred from a clone as part of his daily production.
The farmer did not want his name to be disclosed because he feared Britons saw cloning as "distasteful" so buyers would stop taking his milk if they knew who he was.
The FSA said in response that it regarded meat and products from cloned animals and their offspring as "novel foods" which need to be authorised before being put on sale.
"The agency has not received any applications relating to cloning and no authorisations have been made," a spokeswoman said.
"The agency will, of course, investigate any reports of unauthorised novel foods entering the food chain."
Peter Stevenson, from campaigners Compassion in World Farming, said he was "extremely concerned" at the report and called for an outright ban on the sale of food from cloned animals and their offspring.
He said: "The Food Standards Agency must act quickly to trace this milk and get it withdrawn from shops. The cloning of farm animals can involve great suffering."
Emma Hockridge of the Soil Association, which campaigns for organic farming, added there were other concerns related to the safety of products from cloned animals and that they could reduce genetic diversity.
But Dairy UK, which represents the industry in Britain, insisted there was no danger.
"Milk and meat from the offspring of clones does not present any food safety risk," it said in a statement.
"The European Food Safety Authority has concluded that there is no difference in food safety between meat and milk from the offspring of cloned animals and products from conventionally bred animals".