The man who received the world’s first pig-to-human heart transplant has a criminal record after stabbing a man seven times in the 1980s, according to the Washington Post.

David Bennett Sr was previously told he was ineligible for a transplant, the Independent reports, but was offered the chance of having a non-human heart put in his body instead.

The 57-year-old from Maryland had been admitted to hospital weeks ago after suffering from a ‘life-threatening’ case of heart arrhythmia, and was placed on a heart-lung bypass machine to keep him alive.

The team at University of Maryland Medical received emergency approval from the Food and Drug Administration to input a genetically-modified pig’s heart into his body, and sourced an organ from a 108-kilogram animal.

Since the news of the successful transplant, the sister of a man Bennett was convicted of stabbing in 1988 had come forward to criticise the transplant, saying her brother was never given the second chance Bennett received.

Credit: University of Maryland School of Medicine

Edward Shumaker was left paralysed after being stabbed seven times by Bennett in a bar, and spent 19 years using a wheelchair. In 2005, he had a stroke and died two weeks later, just one week before his 41st birthday.

His older sister Leslie Shumaker Downey said she felt it was unfair that Bennett had received the ground-breaking treatment, writing in a public Facebook post: “That so called man that stabbed my brother 7 times, paralyzing my brother.

“My brother lived a very hard and painful 19 years after it. My brother Edward Shumaker Jr suffered so many things from infections, bed sores you could fit your fist into, MRSA, Sepsis and a stroke that eventually left my brother with a child’s mental capacity.”

She then continued: “I was told by someone a bit ago that it doesn’t matter what Bennett did because it’s unethical to refuse treatment to Bennett because he’s simply a human.