Surgeons in the United States say the first living patient who received a genetically modified pig kidney has died two months after the transplant operation.

Massachusetts General Hospital made the announcement on Saturday. It did not provide details, but said it has no indication that the patient's death was the result of his recent transplant.

On March 16, a surgical team at the Boston hospital transplanted the organ into a man with kidney disease. He was 62 years old at the time. The organ was genetically altered to prevent rejection.

The recipient recovered well and was allowed to go home in April.

Following his death, his family said in a statement that they feel "comforted by the optimism he provided patients desperately waiting for a transplant."

Efforts are underway in the US to develop ways to transplant genetically modified pig organs into humans.

In 2021, a team of US doctors transplanted a genetically modified pig kidney into a brain-dead patient.

The Massachusetts General team says the March surgery was the world's first gene-edited pig kidney transplant into a living patient.

In 2022, a patient who had no other treatment options received a transplant of a genetically modified pig heart. The patient died about two months after the operation.