Animal welfare campaigners are angered by the news that monkeys have been cloned to be used as animal research models.
Two identical long-tailed macaques - called Zhong Zhong and Hua Hua - were born some weeks ago at a lab in China.
According to scientists, genetically identical monkeys will be 'useful' in researching human disease.
Animal Free Research UK, an organization that wants to replace all testing with non-animal methods which are human-relevant, says it is 'angered' by the news.
A spokesperson said: "Zhong Zhong and Hua Hua have no idea yet of the horrifying life they have been born into.
"A life of having cruel experimental procedures inflicted upon them, of living with artificial human diseases that have been injected or surgically put into them.
"A life of not understanding why they are in so much pain, why they are no longer hungry or why they can’t go outside and play."
According to Animal-Free Research UK, the animals will 'suffer unnecessary pain, and ultimately death' - for experiments which might not even be relevant for humans.
While trying to create the cloned monkeys, other animals died: 79 attempts were made, and two other monkeys initially cloned from a different type of cell did not survive.
Animal-Free Research UK says: "Why is society investing in creating new lives to experiment on, when we can instead invest in creating human-relevant research methods to advance biomedical science?"