Steve Smith has apologised for a "serious error of judgement" in a tearful press conference at Sydney Airport.

The deposed Test skipper arrived in Sydney on a Singapore Airlines flight after being sent home in disgrace from South Africa over the ball-tampering scandal.

"Tonight I want to make clear that as captain of the Australian cricket team, I take full responsibility," he said.

"It was a failure of leadership - my leadership. I'll do everything I can to make up for my mistake."

Former Test captain Steve Smith admitted the ball tampering scandal was a "failure of leadership" in a tearful press conference at Sydney Airport. (9news)

Smith's father offered a supportive hand on his shoulder as the former cricketing captain broke down in tears. (9NEWS)

"Good people make mistakes, and I've made a big mistake by allowing this to happen." (9NEWS)

Smith broke down on several occasions as he spoke, saying it was a privilege and honour to represent his country as captain of the Australian cricket team.

"Cricket is the greatest game in the world. It's been my life and I hope it will be again," he said.

"I'm absolutely devastated."

Asked what had gone through his mind on the day of the incident, Smith said, "good people make mistakes, and I've made a big mistake by allowing this to happen."

Cameron Bancroft asked for forgiveness from the community in a moving press conference. (9news)

He confirmed that to his knowledge, it was the first time the Australian team under his captaincy had ever tampered with the ball.

"I'll do everything I can to make up for my mistake. If any good can come of this, if it can be a lesson to others, I hope I can be a force for change," he said.

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

Rookie opener Bancroft, 25, touched down in Perth this afternoon before expressing his "extreme disappointment" in his own actions at a press conference with WACA CEO Christina Matthews.

"I know I'm a role model and I've not acted like one in this instance. I understand the disappointment in the broader community." he said.

"Words don't mean much in these circumstances so I'll be focusing on my conduct and my actions going forward. All I can do in the short term is ask for forgiveness."

David Warner has apologised for his role in the ball-tampering saga. (Getty) (AAP)

He said he knew it would be a difficult journey back to playing Test cricket.

"The thing that breaks my heart the most is that I've just given up my spot in the team to somebody else," he said.

He said he was determined, however, to return to national representation.

Ms Matthews said that while Bancroft had made a "dreadful mistake", she and the WA cricket family would help him through this difficult time.

Bancroft said he was ashamed of not having stood by his values and principles.

"It's completely how cricket shouldn't be played," he said.

David Warner, who has been dropped by sponsors Asics and LG since the scandal broke, apologised to cricket fans on Twitter and Instagram today.

"To cricket fans in Australia and all over the world: I am currently on my way back to Sydney. Mistakes have been made which have damaged cricket. I apologise for my part and take responsibility for it," the post read.

Cameron Bancroft landed in Perth this afternoon. (9NEWS) (9NEWS)

Warner has been banned from representing Australia for 12 months. (AAP) (AAP)

Cricket Australia says Cameron Bancroft was instructed on how to tamper by David Warner. (Getty) (Getty)

"I understand the distress this has caused the sport and its fans. Its (sic) a stain on the game we all love and I have loved since I was a boy. I need to take a deep breath and spend time with my family, friends and trusted advisers. You will hear from me in a few days."

Warner, 31, was banned for 12 months along with Steve Smith for their roles in the ball-tampering scandal.

Bancroft copped a nine-month suspension for his involvement.

A bombshell media release yesterday from CA revealed it was sandpaper, not sticky tape, that Bancroft used to work on the ball under Warner's instruction during the third Test against South Africa.

Smith, Warner and Bancroft will be barred from representing Australia, their states and Big Bash League franchises during the bans, but will be encouraged to play grade cricket.

But CA's board has determined Warner, who has fallen out with teammates over the ball-tampering saga, will never hold another leadership position again.

Warner's broken relationship with his teammates has led to suggestions he may never represent his country again.

Smith and Warner have also been barred from representing their Indian Premier League franchises in 2018, meaning they will forfeit their $2.4 million contracts for this season.

STEVE SMITH'S STATEMENT IN FULL

"Good evening, thanks for coming. I appreciate it."

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

"What happened in Cape Town has already been laid out by Cricket Australia."

"Tonight I want to make clear that as captain of the Australian cricket team, I take full responsibility. I made a serious error of judgment and I now understand the consequences."

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

"If any good can come of this, if it can be a lesson to others then I hope I can be a force for change."

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

"I've been so privileged and honoured to represent my country and captain the Australian cricket team. Cricket is the greatest game in the world. It's been my life and I hope it can be again."

"I'm sorry and I'm absolutely devastated."