SYDNEY, Australia — Disgraced in a blatant ball-scuffing scandal that has transfixed the cricket world, one of its most exalted players flew home to Australia from South Africa on Thursday and broke down in tears, apologizing on live national television for sullying his country and its national pastime.

“I know I’ll regret this for the rest of my life,” said the athlete, Steve Smith, who until a few days ago had been the Australia team’s heroic captain. “I’m absolutely gutted.”

“I hope in time I can earn back respect and forgiveness,” Mr. Smith told a news conference at the Sydney airport as he struggled to keep his composure, his father standing behind him. “Cricket is the greatest game in the world. It’s been my life, and I hope it will be again.”

Mr. Smith returned to Australia five days after admitting to having concocted a plot with teammates to doctor the cricket ball by scuffing it with sandpaper during a match with South Africa last weekend. Scuffing can make the ball act unpredictably, making it more difficult for batsmen to hit. The cheating was caught on video.