The cloned sniffer puppies have already shown their potential
The world's first cloned sniffer dogs have begun training in South Korea.
Seven puppies have been created using cells taken from a labrador considered by customs officials to be their best sniffer dog.
The puppies were born last year after the country's customs service paid a biotechnology company to reproduce a Canadian Labrador Retriever.
Their handlers say they are already showing the same high level of skill as the original dog.
Only about 30% of naturally-born sniffer dogs make the grade, but South Korean scientists believe that could rise to 90% using the cloning method.
The puppies were born to three surrogate mothers after scientists used the nuclei of somatic cells from a sniffer dog called Chase. The state-funded project cost about 300m won ($300,000; £150,000).
A spokesman for South Korean customs said the pups have passed the first round of tests for behavioural patterns and genetic qualities and will report for duty in June after completing a second round of training.