ACT Brumbies lock Shawn Mackay has died in hospital in Durban after being hit by a car late last month, the club said on its website.
Mackay had woken up from a medically induced coma last week after suffering spinal injuries and a broken leg when struck by a car in the South African coastal city.
His death had come despite showing "positive signs of recovery", Brumbies Rugby CEO Andrew Fagan told the Brumbies' website (www.brumbies.com.au).
"Shawn contracted an infection of his bloodstream after his surgery. He deteriorated rapidly, and suffered a cardiac arrest from which he didn't recover," Fagan said.
"This is devestating news for his family and for all of us in the Brumbies community. Our thoughts and prayers are with his family at this difficult time."
Mackay had undergone surgery to his spine and had started communicating with doctors and family through blinking.
Mackay was recruited by the Brumbies this season after spending the past five years playing rugby league in Sydney.
He was selected as a reserve for the Brumbies against the Sharks but came off the bench to play in his team's 35-14 loss.
He was struck by a car while returning to the hotel with team mates in the early hours of the morning.