Faf du Plessis has received no sympathy from his fellow South African Dave Richardson, with the ICC boss describing his ball tampering from the Hobart Test as "pretty obvious".
The Proteas captain was fined 100 per cent match fee fine on Tuesday after he used saliva to shine the ball with a mint in his mouth during last week's second Test win over Australia.
Du Plessis avoided suspension and is free to play in the day-night third Test in Adelaide beginning on Thursday, but the Proteas have vowed to appeal his guilty verdict.
Richardson said the governing body needed to draw a line in the sand over the issue.
"Probably in this case in particular, we drew the line," ICC chief executive Richardson told the Nine Network on Wednesday.
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"We said, 'we need to charge' because in our eyes anyway it was pretty obvious that he was using the residue from the sweet directly on the ball.
"I think the bottom line is if you want to change the condition of the ball by polishing it, in other words improving it, keeping it, retaining its condition, do so, but don't use any artificial substance."
Du Plessis was fined approximately $2500 after a three-hour ICC hearing at Adelaide Oval on Tuesday.
He risks a tougher penalty if he appeals.
It was the second time the batsman has been found guilty of ball tampering in three years.
Richardson, a former South African wicketkeeper, also condemned Proteas officials for their involvement in ugly scenes at Adelaide airport on Monday.
Security official Zunaid Wadee was attempting to shield du Plessis from questions regarding the mint controversy when he physically clashed with Nine Network reporter Will Crouch.
Richardson said it was the first time he had seen the footage.
"Well, security guards, tend to be a bit vicious on occasions," he said.
"The whole thing is unnecessary, really.
"It's been a great series from South Africa's point of view it will be a pity if the third Test (ruins) a great occasion in Adelaide coming up."
Richardson is in Sydney to present Australia's women's team their world championship trophy at the Southern Stars' third one-day international against South Africa at North Sydney Oval on Wednesday.
