Cricket Australia found all three players guilty of breaching article 2.3.5 of CA’s code of conduct and they will not take part in the rest of the tour of South Africa.
Smith has been stripped of the test captaincy for the remainder of this series with Tim Paine to take over as the 46th Test captain for Australia after he took on the role on day four of the Test in Cape Town.
Cricket Australia CEO James Sutherland fronted the media in Johannesburg overnight to discuss the investigation being conducted by CA Head of Integrity.
“Earlier today (Tuesday), I received an update about the investigation being conducted by our Head of Integrity Iain Roy and in conducting his interviews he was accompanied by two ICC integrity officers,” Sutherland told reporters.
“While that investigation is not complete, preliminary findings have been considered and discussed by the CA board earlier today.
“The key finding is that prior knowledge of the ball tampering incident was limited to three players: Captain Steve Smith, vice-captain David Warner and Cameron Bancroft.
“No other players or support staff had prior knowledge and this includes Darren Lehmann, who despite inaccurate media reports, has not resigned from his position.
“He will continue to coach the Australian men’s team under his current contract.”
Sutherland also revealed that “significant” sanctions for Smith, Warner and Bancroft will be announced within the next 24 hours.
“The players involved have officially been reported for breaching Cricket Australia’s code of conduct under article 2.3.5.,” Sutherland said.
“The substance of the offence can be covered by terms and I paraphrase somewhat from the article: Conduct at any time that is contrary to the spirit of the game, unbecoming of a representative, harmful to the interests of the game, or brings the game into disrepute.
“Once the investigation has concluded in the next 24 hours, sanctions will be announced and will go through the Cricket Australia code of conduct process.”
The International Cricket Council had already laid sanctions down to Smith who received a one match ban and Bancroft who was fined and handed three demerit points to his disciplinary record.
Smith has played in all of the last 59 Test matches for Australia in which he has scored 23 centuries.
This will be the first time Smith has missed a Test since March 2013.
The show must go on and Australia will play the final match of the series against South Africa which begins on the 30th of March in Johannesburg.