Dr Mahesh Goel, 39, whose address was given as Burnley General Hospital, and consultant urologist John Roberts, 59, of Swansea, both pleaded not guilty at Swansea Crown Court to the unlawful killing of Graham Reeves.

Mr Reeves, of Burry Port, West Wales, was 70 when he died on March 1 last year five weeks after having the wrong kidney removed during an operation at Prince Philip Hospital, Llanelli.

At an earlier hearing it was said that Mr Roberts had overseen the operation and placed Mr Reeves on the operating table. The actual incision and removal of the healthy kidney is alleged to have been performed by Dr Goel.

Mr Reeves developed septicaemia caused by bacteria and toxins in the blood and his condition deteriorated. The diseased kidney then had to be removed.

The two surgeons will appear in court again on January 18 for a further hearing in preparation of the trial.

They were both remanded on unconditional bail by Judge John Diehl.

Father-of-two Dr Goel has an address in the grounds of Burnley General Hospital but does not and never has worked for Burnley NHS Trust. His wife is also a doctor.

Two inquiries were launched after Mr Reeves' death, an internal one by the Carmarthenshire NHS Trust and an independent investigation by the Royal College of Surgeons.

Although both have been completed the findings are being withheld pending the outcome of the crown court case.