All-Ireland-winning footballer and RTÉ analyst Joe Brolly has spoken of the devastation he suffered on hearing his kidney donation to a friend had failed.

The 43-year-old barrister from Derry told RTÉ News at One it was an agonising time but he "would do it all again tomorrow if he could".

The organ that was transplanted to Shane Finnegan last month stopped working when complications were discovered nine days after the major operation.

Brolly said Shane's wife called in the middle of the night to tell him the operation had failed. He said despite claims Shane's body had rejected the organ, the kidney was in fact starved of oxygen because of a blood clot.

"There was obviously deep disappointment," he said. "The kidney that had been working perfectly had to be taken out. There was no rejection as we understand it. It was all the more agonising for that.

Brolly said he "would be trying to get on", adding that he has started back running and hoped to return to work next month.

"I would do it all again tomorrow if I could" - Joe Brolly

"But for Shane it's different" he said. "Because the stakes are very high, it wasn't really the sort of game you could afford to lose. For Shane, it was obviously was a hammer blow.

"The clock is ticking and he needs a kidney from a live donor urgently. He is very weak, he has lost a few stone and is very frail but mentally he is very strong."

Brolly insisted people should not be afraid of being a living donor.

"The scientific community isn't sure why we have two kidneys," he added. "You only need one kidney. Once you are healthy, you can be a living donor.

"If someone were interested, they can easily contact me, north or south. If someone put their hands up, the process is excellent, you know it's something well worth doing. I would do it all again tomorrow if I could."

He said it's been a great lesson for his children and the wider community, including St. Bridget's GAA club, where both he and Shane coached at under-age level.

During his time in hospital he said: "You could see lives being saved everyday".

There are currently 600 people in the Republic waiting for a kidney transplant, 200 in Northern Ireland - including Shane Finnegan.

Brolly added: "Between eight and 10 percent of those will die without getting a kidney and it's an awful waste, because if people filled out a donor card, it would make a massive, massive difference to other people's lives."