Sydney - Australia's Prime Minister has called for an end to sledging in cricket, saying it was "right out of control" as he urged the sport to clean up its image amid a ball-tampering scandal.

Malcolm Turnbull described the cheating crisis in which captain Steve Smith admitted to masterminding a plot to change the ball's condition during the third Test against South Africa on Saturday as a "shocking affront to Australia".

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He demanded Cricket Australia act decisively in investigating the incident. The governing body is expected to provide an update on Wednesday.

Turnbull added that authorities needed to crack down on sledging - verbal abuse involving players on both sides - if it wanted cricket to "once again (be) held up as a role model".

"I think there has to be the strongest action taken against this practice of sledging," he told reporters in Canberra. 

"It has got right out of control ... it should have no place (in cricket).

"The game of cricket ... should be one that once again is held up as a role model."

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The Test series between South Africa and Australia was ill-tempered even before Saturday's explosive admissions.

The first Test in Durban earlier this month was plagued by an ugly row between vice-captain David Warner and South Africa's Quinton de Kock.

CCTV footage showed Warner being restrained by team-mates as he appeared to lose his temper during a confrontation on a staircase as the players walked to their dressing rooms.

The incident was reportedly over a jibe about Warner's wife Candice, with the Australian describing the remark as "vile and disgusting".

Both players were punished for the bust-up with Warner fined 75 percent of his match fee and De Kock 25 percent.

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The recent Ashes series was likewise marred by tensions between Smith and England bowler James Anderson, with umpire Aleem Dar having to separate the pair when the Australian was batting.

Anderson described the Aussies as bullies who overstepped the line ahead of the Adelaide Test, with Smith retorting that the Englishman was one of the biggest sledgers in the game.