David Warner has broken his eight-year silence and says it is "100% accurate" that every player knew of the sandpaper plot, giving "full support" to Usman Khawaja.
The former vice captain of the Test team also claimed Cricket Australia's investigation was "rushed and botched", as he backed his former teammate's account in a social media video shared on Monday evening.
Khawaja wrote in his autobiography Sabr, out on Tuesday, that his teammates should accept collective responsibility for the incident and that more details are still not public.
The claims have resuscitated calls for players – including Test captain Pat Cummins – to address if they had any knowledge about the use of sandpaper to help the ball swing on the 2018 tour of South Africa.
Cummins and current ODI captain Mitchell Marsh were part of the Australian side in Cape Town when Cameron Bancroft was caught applying sandpaper to the ball, an act which saw him – as well as captain Steve Smith and vice-captain David Warner – suspended.
The book also revealed Warner's frustration at the 2021 media statement issued by the bowlers who played in the match, including Cummins, claiming they did not know "a foreign substance was taken onto the field to alter the condition of the ball" until images appeared on the big screen at Newlands.
Speaking on Instagram, Warner endorsed Khawaja's account.
"Uzzy, I throw my full support behind you," Warner said.
"I thank you for what you've done. It's a hundred percent accurate what you've said. Now everyone knows the truth."
Warner had previously avoided the topic of Usman Khawaja's book since its claims were published on Saturday in multiple media appearances in Nepal, where he plays for the Kathmandu Gorkhas in the third edition of the Nepal Premier League.
"I'm not writing [this chapter] because I think it will help the sales of my book – if it was for sales, I could write another 10 pages about it," Khawaja wrote in the 21-page section titled "Sandpaper". "But I still don't think it's right that those three boys copped all of the brunt."
Marsh will be the first current player to face the media since extracts of Khawaja's book were published this week, as his side prepares for a series against England that marks the start of the Australian summer's international competition.
Khawaja also claimed that in a meeting with the players, it was put to the group the trio had "put their hands up to cop it" because "apparently, we had to look after the coaches, because they were more vulnerable than us".
Then-coach Darren Lehmann, who resigned at the end of the series and is now an ABC commentator, denied knowing the extent of his side's ball-tampering. "You know something's going on because that's been happening for a long period of time, but not to the extent, and that'd be everyone, I imagine. Everyone would think something's going on, but what do they know? That [is something] only an individual can answer."
Former Australia captain Mark Taylor said on Sunday he was disappointed in Khawaja's decision to revisit the incident in his book, and warned Cummins would also have to face the media in the coming weeks.
"That's why I'm disappointed, because it's now going to overshadow the summer ahead," he told Channel Nine. "It will be obviously very tough for Pat and the bowlers because they're going to have to answer further ongoing questions which they've now done for eight years."
Marsh is due to address the media in his customary preview press conference on Thursday, before the first ODI in Perth on Friday.
Khawaja's autobiography alleges knowledge of the ball-tampering extended beyond the banned trio. The book includes an allegation that two players refused to take collective responsibility for the wrongdoing, and that a coach encouraged Bancroft to tamper with the ball.
Cricket Australia responded to the claims made in Khawaja's book with a statement on Saturday. "All relevant information presented to CA to date has been properly considered and we remain comfortable with the findings of our integrity process," a CA spokesperson said.