Scientists who created two genetically-identical monkeys at a laboratory in China have been accused of paving the way for the "creation of human clones".
Campaigners say there will no doubt be billionaires around the world who will take this breakthrough as an invitation to explore options for making themselves a double.
The long-tailed macaques named Zhong Zhong and Hua Hua have become the first primates to be cloned using the DNA-transfer technique that birthed Dolly the Sheep 20 years ago.
Their lab coat-wearing parents are hoping it will open the door to populations of genetically-uniform monkeys that can be used for ground-breaking research in human disease.
#BREAKING: China successfully clones world's first macaques from somatic cells by method that made Dolly the sheep 20 years ago (Photos provided by Chinese Academy of Sciences) pic.twitter.com/kg4myOwsZP— China Xinhua News (@XHNews) January 24, 2018
But campaigners have hit out at the research, insisting it was a step towards the eventual cloning of humans – and that it involved unacceptable levels of cruelty to animals.
"Although it looks like that would be technically difficult, those with enough financial resources and the ambition to be the first to create a cloned child are likely to try," he adds:
"There would undoubtedly be a market for human clones."
The London-based watchdog group, who have been "informing people about human genetics issues" since 1999, has called for an international ban on the cloning and genetic engineering of humans.
"The scientists themselves admit that their work has involved the abnormal development – and death – of many monkeys before and after birth," she told the Press Association.
The two young cloned macaques are the public face of tens of thousands of failed attempts, hundreds of monkeys involved, and a significant catalogue of animal suffering - with the promise of more to come: https://t.co/FnAPK7fuVX— RSPCA - Lab Animals (@RSPCA_LabAnimal) January 25, 2018
But Dr Qiang Sun, the director of the Non-Human Primate Research Facility that created the cloned monkeys insists that the pros will ultimately outweigh the cons.
He said the ability to clone monkeys would allow scientists to create real, human-like models, which they could use to trial out cures for brain diseases, cancers and metabolic disorders.
"[It will] allow us to test the efficacy of the drugs for these conditions before clinical use," he explains.
Dolly made history in 1997 when she became the first 'successful' clone of a mammal from an adult cell – taken from the udder of a Finn Dorset sheep.
Since then, however, a bunch more animals have been cloned using the same somatic cell nuclear transfer (SCNT) technique – including cattle, pigs, dogs, cats, mice and rats.