Batsman David Warner says he is "resigned to the fact" he may never play for Australia again after his part in the ball-tampering scandal.
Warner and Steve Smith were given year-long bans by Cricket Australia after the incident against South Africa.
The 31-year-old apologised on Saturday, saying he took "full responsibility for my part in what happened."
He added: "I have only ever wanted to bring glory to my country through playing cricket."
Smith and Cameron Bancroft, who received a nine-month ban for his role in the plan to tamper with the ball by using sandpaper during the third Test, had earlier apologised for their part in what happened.
Reading from a statement, an emotional Warner told a news conference: "To all Australians, cricket fans or not, I apologise for my actions and I am sorry for the impact those actions have had on our country's reputation.
"It is heartbreaking to know I will not be taking the field with teammates I love and respect and that I have let down.
"It is something I will regret for as long as I live."
What did Warner say?
Addressing the media for the first time since the incident, Warner said that:
He had a "tiny ray of hope" he might play for Australia again, but he was "resigned to the fact that may never happen"
He "fully supported" Cricket Australia's (CA) review into team culture
He would "seek out advice and expertise to help me make serious changes"
And he was responsible for "my actions and the consequences it brings".
He did not directly answer questions about whether any other members of the Australian team had been involved in the plan to tamper with the ball, instead restating that he was there to take responsibility for his own actions in Cape Town.
Warner later posted on social media that he would do his best "in time" to answer questions people may have.
"There is a formal CA process to follow and I am taking advice to make sure I properly comply with that," Warner tweeted.
"I should have mentioned that in my press conference, I'm sorry for not making it clearer."
Describing the Australian team as his "family", Warner said he would miss being on the field with them for the next 12 months.
Prior to the ball-tampering saga, Warner was fined by the International Cricket Council after an altercation with South Africa wicketkeeper Quinton de Kock.
Warner later said that "vile and disgusting" remarks made by De Kock against Warner's wife, Candice, had prompted the incident.
Speaking in Sydney, Warner said the wellbeing of his wife and their two daughters was "foremost in my mind".
"We let our country down, we made a bad decision. I really regret what happened on that day three," Warner added.
"We know what the consequences are when you make horrible decisions like this."
How did the ban happen?
CA's investigation found that vice-captain Warner had instructed fellow opener Bancroft to carry out the plan to scratch the ball with sandpaper, and had demonstrated to him how to do it.
The duo, along with captain Smith, were subsequently banned from all international and Australian domestic cricket - while Smith and Warner will not play in the forthcoming Indian Premier League season, and resigned as captains of their IPL franchises.
Warner will not be considered for any Australian team leadership positions in the future, while Smith and Bancroft have been suspended from captaincy for at least the next two years.
Smith denied his side had tampered with the ball before, following suggestions that similar tactics were employed in the recent Ashes series against England.
CA found that coach Darren Lehmann did not know about the plan, but he will step down after the fourth Test against South Africa, which began on Friday.