It sounds like something out of a sci-fi movie – but researchers in Japan say they are very close to being able to grow human organs inside pigs, the Telegraph reported.

By injecting stem cells from humans into pig fetuses, the researchers say they have already managed to produce pigs that were able to generate human blood. In addition, they also injected stem cells from rats into embryos of mice that had been genetically altered not to produce their own organs. As a result, the scientists created mice that had rat organs.

Professor Hiromitsu Nakauchi, director of the center for stem cell biology and regenerative medicine at the University of Tokyo, and who led the research, hopes this technique could allow pigs to grow human organs, which could significantly cut the waiting lists for transplants.

"The technique, called blastocyst complementation, provides us with a novel approach for organ supply,” Nakauchi said. “We have successfully tried it between mice and rats. We are now rather confident in generating functional human organs using this approach."

Nakauchi presented the findings at the annual conference of the European Society of Human Genetics.

Click here to read more about the study from the Telegraph.