Scientists have created the first human-pig hybrids in a breakthrough which could pave the way for doctors to grow an unlimited supply of organs for transplants.

Britain is currently facing a crisis in organ donation because the number of deceased donors is dropping as advances in medical care mean more lives are saved.

In the past scientists thought they might be able to use the organs of pigs, which are roughly the same size of those of humans, but could not prevent the immune system rejecting animal tissue.