Steve Smith, Cameron Bancroft and David Warner were the only people with any prior knowledge of the ball-tampering plot that has rocked Australian cricket, according to Cricket Australia (CA) CEO James Sutherland.

Bancroft's use of tape to alter the condition of the ball in the third Test against South Africa has made international headlines and attracted strong and widespread criticism, including from Australian prime minister Malcolm Turnbull.

Explaining the incident on day three of the Test, Smith claimed the "players and the leadership group" had come up with the scheme, which led to speculation regarding the make-up of the team's band of senior players.

However, a CA investigation has found knowledge of the cheating was limited to the three players already named, seemingly dismissing Smith's version of events.

"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," Sutherland told a news conference.

"No other players or support staff had prior knowledge and this includes [coach] Darren Lehmann."

Smith and Warner have already been stood down from their captaincy roles, while the former has been banned for the remaining Test of the series and replaced as skipper by Tim Paine.

Bancroft was free to feature after receiving three demerit points and being fined 75 per cent of his match fee, but all three players have now been sent home from South Africa, pending potentially "significant" sanctions which are expected to be announced in the next 24 hours.

"In view of the broader reputational and integrity issues involved, the sanctions that will be contemplated are significant," added Sutherland. "The process must therefore be thorough to ensure that all relevant issues have been examined.

"I understand the appetite for urgency given the reputation of Australia as a sporting nation has been damaged in the eyes of many. However, urgency must be balanced with due process given the serious implications for all involved.

"In addition to sanctions for individuals, Cricket Australia will initiate an independent review into the conduct and culture of our Australian men's teams.

"We will have more to say about this review in the coming days, but it will be conducted by an expert panel who will report to the Cricket Australia board."

Sutherland also confirmed that Lehmann will continue as coach, rubbishing earlier reports that he would resign from his position.