Cricket Australia CEO James Sutherland has dispatched his integrity officer to South Africa to urgently investigate ball-tampering by the Australian cricket team that left him “extremely disappointed and shocked”.

Captain Steve Smith is under immense pressure after he revealed that on day three of the third Test against South Africa in Cape Town, he and his leadership group discussed and approved ball-tampering, with youngster Cameron Bancroft, playing just his eighth Test, doing the dirty work.

Bancroft was spotted on television cameras and later quizzed by umpires. By then, though, he’d hidden the offending tape down his pants.

His bizarre attempt to hide the evidence was also picked up by eagle-eyed camera operators in South Africa.

In a tense press conference after stumps on day three, both Bancroft and Smith admitted to cheating.

Smith’s captaincy seems in major doubt after Sutherland opened an investigation, ordered it to be dealt with as soon as possible, and slammed those involved for instigating “a very sad day for Australian cricket”.

It was announced before the start of the fourth day’s play that Smith and vice-captain David Warner will stand down as leaders for the rest of the third Test. Tim Paine will lead Australia.

“I was extremely disappointed and shocked to hear the news,” Sutherland told reporters on Sunday.

“From a Cricket Australia perspective, we regard this as an extremely serious issue.

“We have a responsibility to take this further … over the next couple of days, [we will] get a deep understanding of what happened and why.”

Sutherland has sent his head of integrity, Iain Roy, and high performance manager Pat Howard, to South Africa to “gather the relevant information”.

He assured cricket fans it would be “dealt with as a matter of urgency and seriousness”.

.@CAComms CEO James Sutherland says it's important that Cricket Australia 'does not jump to conclusions' and understand all the facts before making a decision.

MORE: https://t.co/GxcaR0jvGy pic.twitter.com/IEA1fOrtAI

— Sky News Australia (@SkyNewsAust) March 25, 2018

He refused to say if Smith would remain Australia’s captain, insisting that “we need to understand the facts before we make decisions”.

He said he had not spoken with the skipper but that “he will know” the gravity of the situation.

Sutherland also made clear how disappointed he was with the behaviour of Australian players in the latest farce of what has been an ill-tempered series.

It seems highly unlikely Smith will keep his job – and coach Darren Lehmann and other members of the leadership group are sure to be questioned over their roles in what is being called the worst moment in the history of Australian cricket.

‘I am incredibly sorry’

Speaking after play in Cape Town, Smith said: “The leadership group knew about it. We spoke about it at lunch. I am not proud of what’s happened.

“It’s not within the spirit of the game. My integrity, the team’s integrity and the leadership group’s integrity has come into question. It won’t happen again.

“[It was a] poor choice and we deeply regret our actions. The coaches weren’t involved … this is the first time it has happened under my leadership.

“It’s such poor actions. Deeply regrettable and won’t happen again. I can promise you … I am embarrassed. Being the leader, I am incredibly sorry.”

Smith said, though, that he didn’t feel he needed to resign from his role as captain.

“I won’t consider stepping down. I still think I am the right person for the job,” he said.”

Bancroft and Smith are spoken to by umpires. Photo: Getty

Smith first captained Australia at Test level in December 2014, before taking on the role on a full-time basis in August 2015.

Also speaking after day three, Bancroft fessed up and said he had already been charged by the ICC.

“We had a discussion during the break and I saw an opportunity to use some tape, get some granules from the rough patches on the wickets and change the condition. It didn’t work. The umpires didn’t change the ball. I was cited on the screen and that resulted in me shoving it down my trousers.”

Prime Minister weighs in

The scandal also reached the highest office in the land, with PM Malcolm Turnbull expressing his shock and disappointment.

Mr Turnbull said he had spoken with Cricket Australia chairman David Peever and “expressed to him very clearly and unequivocally my disappointment and my concern about the events in South Africa”.

“Our cricketers are role models and cricket is synonymous with fair play,” he told reporters on Sunday.

Malcolm Turnbull said the cheating scandal “beggars belief”. Photo: AAP

“How can our team be engaged in cheating like this? It beggars belief.”

Meanwhile, Australian Sports Commission chairman John Wylie and CEO Kate Palmer also strongly condemned the cricket team’s behaviour, and called for Smith to stand down immediately.

“The ASC condemns cheating of any form in sport. The ASC expects and requires that Australian teams and athletes demonstrate unimpeachable integrity in representing our country,” they said in a statement.

“The Australian cricket team are iconic representatives of our country. The example they set matters a great deal to Australia and to the thousands of young Australians playing or enjoying the sport of cricket and who look up to the national team as role models.”

“Given the admission by Australian captain Steve Smith, the ASC calls for him to be stood down immediately by Cricket Australia, along with any other members of the team leadership group or coaching staff who had prior awareness of, or involvement in, the plan to tamper with the ball.”

‘It’s pre-meditated cheating’

Cricket figures from across the world expressed their dismay with the behaviour, with former Australia captain Michael Clarke telling the Nine Network: “It’s pre-meditated cheating. It’s blatant cheating. It’s disgraceful.”

Spin king Shane Warne added on Twitter: “Very disappointed with the pictures I saw.”

Ex-England skipper Michael Vaughan said: “The more you think about what has happened in Cape Town the more I realise the leadership needs to be replaced … positions are untenable and I say that with the utmost respect for that group.”

Injured South Africa bowler Dale Steyn expressed a similar view: “You know nothing in professional sport is done without the consent of your captain and coach … tough times ahead.”

South Africa is 5-238 in its second innings in Cape Town, leading by 294 runs. The four-Test series is locked level at 1-1.