Johanesburg: To the 'disappointment' of the ICC, South Africa captain Faf du Plessis has appealed the guilty verdict against him for ball tampering in the second test against Australia.



Cricket South Africa says Thursday that Du Plessis and his lawyers studied the written decision made by match referee Andy Pycroft before deciding to formally appeal.



Du Plessis was found guilty of ball tampering after TV replays showed him applying saliva to the ball while sucking a mint, breaching rules which prevent players applying foreign substances to the ball's surface.



He was fined his match fee but escaped a ban. The charge against him was brought by ICC chief executive Dave Richardson.



Du Plessis claimed it was common for cricketers to do what he did and that he was being unfairly singled out.



Cricket South Africa chief executive Haroon Lorgat said Thursday that Du Plessis was "feeling aggrieved."



The ICC said it was "disappointed" that du Plessis had not accepted the verdict, and stressed that the rules on applying foreign substances to the ball must be applied.



"ICC is disappointed that Faf du Plessis has chosen not to accept the findings of match referee Andy Pycroft and will instead exercise his right to appeal. A Judicial Commissioner will now be appointed to hear the appeal at the earliest opportunity," world cricket's apex body said in a statement.



"Unless the laws are changed, the current practice of charging players when the evidence shows an obvious breach will continue," the ICC said.



Du Plessis hit an unbeaten 118 on the first day of the third test against Australia on Thursday.