He broke down repeatedly during the press conference, particularly when he spoke of the effects on his parents.

"Any time you think about making a questionable decision, think about who you're affecting. You're affecting your parents and to see the way my old man has been and my mom, it hurts," he said.

"To all of my teammates, to fans of cricket all over the world and to all Australians who are disappointed and angry, I'm sorry.

"There was a failure of leadership, of my leadership. I'll do everything I can to make up for my mistake and the damage it's caused.

"I know I'll regret this for the rest of my life. I'm absolutely gutted. I hope in time I can earn back respect and forgiveness."

The crisis engulfing Australian cricket claimed another casualty later Thursday when the team's head coach Darren Lehmann announced that he is stepping down at the end of the final Test match of the series against South Africa.

"As many who sit in this room will know, life on the road means a lot of time away from loved ones and after speaking to my family, it is the right time to step away," Lehmann said. "Speaking to the players and saying goodbye is the toughest thing I have had to do."

Vice-captain David Warner, who was also stripped of his leadership position, posted an apology on social media to "cricket fans in Australia and all over the world" ahead of his arrival, in which he said "mistakes have been made."

He tweeted: "I apologize for my part and take responsibility for it... It's a stain on the game we all love and I have loved since I was a boy." He added that he would speak out "in a few days."

The trio has admitted to conspiring to scuff the ball in an attempt to gain an unfair advantage over South Africa, where the national team is in the middle of a four Test series.

Smith was heckled by cricket fans at Johannesburg's O.R. Tambo International Airport as he departed South Africa.

Crowds yelled "cheat" at the batsman, who refused to answer journalists' questions as a phalanx of police officers ushered him toward the secure area.

Lengthy bans

Smith and Warner have been banned from playing for the national side for a year following their roles in the incident during the third Test against South Africa, which caused national outrage. Bancroft, the junior player, is banned for nine months.

All three players will also have to complete 100 hours of voluntary service in community cricket before being considered for future selection.

While Indian cricket great Sachin Tendulkar tweeted that the bans were the "right decision," others, including Australian cricket legend Shane Warne, have called them too severe a punishment.

Smith and Warner have also been banned from participating in India's domestic cricket league, the Indian Premier League (IPL), in 2018, the country's league and Board of Control for Cricket announced Wednesday.

Earlier Warner had stepped down as captain of SunRisers Hyderabad. On Thursday, the IPL team named New Zealand captain Kane Williamson as his successor, according to a tweet from the SunRisers' account.

Bancroft, too, has been released by Somerset, his English county team as the fallout from the tampering scandal continues.

"Over the last few days, cricket has been shadowed by a very dark cloud," Somerset director of cricket Andy Hurry said in a statement on Thursday.

"I have met this morning with the CEO, Club Captain and Head Coach and with the Club's best interests at the center of our decision can confirm Cameron Bancroft will not be our overseas player for the 2018 season."

The final Test of the series against South Africa kicks off on Friday. The three suspended players will be replaced by Matthew Renshaw, Glenn Maxwell and Joe Burns for the fourth Test, with Tim Paine appointed captain.

Sponsors flee

In the wake of the scandal, the Commonwealth Bank of Australia has dropped Smith as one of its brand ambassadors. The institution in a statement said it will continue to support women's, grassroots and indigenous cricket in partnership with Cricket Australia.

The news comes as sports equipment company Asics also announced the termination of its sponsorship of Warner and Bancroft.

"The decisions and actions taken by David Warner and Cameron Bancroft are not something that Asics tolerates and are contrary to the values the company stands for," Asics said in a statement Wednesday.

Electronics giant LG Australia has also confirmed to CNN Money that it will not renew its sponsorship with Warner.

Watershed moment

John Buchanan, a former coach for the Australian team between 1999 to 2007, told CNN Sport that Cricket Australia was facing a watershed moment.

"There's a feeling in Australia this isn't just a one-off incident," he said. "It's been building over a long period of time and the culture between the team really needs to be addressed really seriously.

"What comes next will be a real test for Cricket Australia with how they deal with this issue."

Cricket Australia CEO James Sutherland apologized on behalf of the organization, to both Australia and South Africa.

"I understand and share the anger and disappointment of Australian fans," Sutherland said during a press conference.

"I want to apologize to all Australians that these events have taken place, particularly to all the kids who love cricket and idolize the players. I want to also apologize to cricket South Africa and South African fans that this issue has overshadowed what otherwise should have been a wonderful series."