Australian cricket was facing perhaps the toughest week in its history on Monday as a backlash grew over a ball-tampering scandal which is likely to cost Steve Smith the Test captaincy.

Sponsors expressed “deep concern” as media and fans called for widespread changes following the shock admission that Smith and senior team members plotted to cheat in South Africa.

Smith, 28, was suspended as skipper for the remainder of the third Test against South Africa on Sunday and was then banned for one match by the ICC.

His team's weekend of shame then ended in a crushing 322-run rout. Set an unlikely 430 to win, Australia were bowled out for a paltry 107 with fast bowler Morne Morkel taking five for 23.

Now Smith is expected to face a harsh sanction from under-pressure Cricket Australia for his role in the plot which saw team-mate Cameron Bancroft tamper with the ball by using yellow sticky tape, before desperately trying to conceal the evidence down the front of his trousers.

Cricket Australia said in a statement on Monday that Smith and all members of the team would remain in South Africa for the time being to assist in its probe into the circumstances around what happened. But Smith, whose talents with the bat have drawn breathless comparisons with Aussie great Don Bradman, is not the only man caught in the crosshairs.

David Warner also stood down from his role as vice-captain, while questions remain over coach Darren Lehmann although Smith said the former Australian international was not involved in the conspiracy.

Pressure was also mounting in Australia for CA chief James Sutherland to take responsibility for the “rotten” team culture and quit.

'Reality has started to sink in'

“It's been a horrible 24 hours — I want to apologise to our fans and those back home,” said Tim Paine, who was handed the stand-in skipper role on Sunday.

“We're struggling but the reality and the enormity of what's happened probably started to sink in. I don't think we expected this to be as big as it has been, the fall-out we have seen from back home.”

Smith, also docked 100 per cent of his match fee by the ICC, will miss the fourth and final Test in Johannesburg from Friday due to his ban. However, Bancroft, the 25-year-old opening batsman, escaped an ICC suspension. He was instead fined 75pc of his fee, warned, and hit by three demerit points.

“The decision made by the leadership group of the Australian team to act in this way is clearly contrary to the spirit of the game,” said ICC chief executive David Richardson. Smith, who was out for just seven runs on Sunday, Warner and Bancroft were loudly booed by fans during Australia's second-innings surrender.

The admission of cheating brought a firestorm of anger, with Australian Prime Minister Malcolm Turnbull saying he was “shocked and bitterly disappointed”.

'Sorry' for cheating

In scathing commentaries on Monday, Australian media said the team had heaped “disgrace and humiliation” on the country, while sponsors also weighed in. "This is deeply disappointing and certainly not what anyone expects from our national cricket team,” airline Qantas, whose logo is on the team shirts in South Africa, told AFP in Sydney. “We are in discussions with Cricket Australia as this issue unfolds.”

Sutherland issued an apology to fans.“To our Australian cricket fans, we are sorry,” he said. “This behaviour calls into question the integrity of the team and Cricket Australia.”

South Africa captain Faf du Plessis, who has himself twice been sanctioned for ball-related offences, gave Smith qualified support for coming clean. “Obviously he's trying to take responsibility so there is right in that but there's also a right in that people are responsible for their own actions,” he said on Sunday.

“I don't know what the right answer is but I can understand it's a really tough time for him to be in right now.” Smith had insisted on Saturday he wouldn't resign the captaincy he has held for three years since succeeding Michael Clarke, but his position appears to be increasingly tenuous.

Several former Australian Test stars have said it was impossible for him to continue, with Clarke insisting Smith had made “a big mistake” and must suffer the consequences. But Clarke added: “I think it's important that we do over time forgive as well.”

Smith on Saturday took responsibility for Bancroft's actions, admitting he was involved in planning the move at lunchtime with “the leadership group”.

“I'm not proud of what happened. It's not in the spirit of the game,” he said.