Researchers in Japan have produced three piglets by cloning a genetically-engineered pig that was developed in the United States for cross-species organ transplants into humans.

A team led by PorMedTec, a venture launched based on the research of Meiji University scientists, announced that the three piglets were born on Sunday.

The researchers said it is the first time that pigs for xenotransplantation of organs into humans have been produced in Japan.

The piglets were cloned from a pig that was developed by a US biotech firm. Its genes were engineered to reduce the risk of rejection by a human recipient.

Research on pig-to-human xenotransplantation has gained more attention in recent years, as it could help secure organs for transplants.

The group plans to supply the piglets to research institutes. The scientists say they aim to start research on transplants of pig organs into monkeys by the end of this year.

Nagashima Hiroshi, a professor at Meiji University and chief scientist at PorMedTec, said he was relieved that the piglets were born without any problems. Nagashima said he expects discussions to pick up in Japan about clinical applications involving pig organs. Nagashima said he will carry on with the research with safety in mind, while seeking to address ethical issues.