ACT Brumbies lock Shawn Mackay has died a week after he was hit by a car in South Africa.

The 26-year-old suffered spinal injuries and a broken leg in the accident, which happened as he left a Durban nightclub with team-mates the day after their Super 14 match against the Natal Sharks.

Mackay had woken up from a medically induced coma last week and started communicating with doctors and family through blinking after undergoing surgery.

But the condition of the former Australia Sevens captain, who had been tipped as a potential Wallabies lock for the future, deteriorated overnight and he died from a bloodstream infection.

The Brumbies players only learned of his death after they returned to Canberra from their three-match tour of South Africa. Coach Andy Friend said: "It's the worst possible news and it's fair to say we're all in shock and we've taken the news very, very hard.

"To hear that the blood infection has led to a cardiac arrest and has taken his life is all very hard for us to reconcile.

"Macca was an outstanding person. When we recruited him we did so for his character as much as his outstanding rugby skills. He had the respect of everybody at the Brumbies and everybody in Australian rugby.

"His death is a tragedy."