Cape Town - International Cricket Council (ICC) chief executive Dave Richardson said the governing body had to draw the line over Faf du Plessis' mintgate controversy and insisted that the decision was "pretty obvious".
Du Plessis was found guilty and fined 100% of his match fee on Tuesday after television footage appeared to show him applying an artificial substance to the ball during last week's second Test against Australia in Hobart.
READ: I'm no cheat, insists Faf
The Protea skipper was cleared to play in the third and final day/night Test in Adelaide on Thursday, however Cricket South Africa (CSA) confirmed that Du Plessis will appeal the ICC's ruling.
Former Protea wicketkeeper Richardson told Nine Network on Wednesday that the ICC have no regrets, despite previous reports of ball tampering claims coming into light since Du Plessis' charge.
"Probably in this case in particular, we drew the line," said Richardson.
"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," said Richardson.
The South Africans take a 2-0 lead into Thursday's final Test at the Adelaide Oval, and Richardson was hopeful that the off-field issues won't take the shine off the Proteas' dominance.
"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," he ended.