Cricket South Africa's board has raised concerns about the Proteas' reputation for ball tampering at its annual general meeting, according to reports in South African media.

Vernon Philander and Faf du Plessis were both fined for ball tampering offences in the past 12 months, prompting CSA's ethics committee to raise the issue.

In comments reported by supersport.com, Board member Vusi Pikoli, a leading figure in South Africa's legal industry, said he was "deeply concerned" at the practice and that "such behaviour cannot be tolerated" from the national team.

"The committee wishes to raise its deep concern (at) the recent reports and allegations of ball-tampering," said Pikoli, CSA's ethics sub-committee chairman.

"The committee takes a very dim view of these reports and wishes to send out a strong message that such behaviour cannot be tolerated. Such conduct damages our fragile reputation.

"It's not about what others do, it's about our reputation, and we urge our lads to take this matter very seriously."

Philander was fined 75 per cent of his match fee after accepting a charge of tampering with the ball "without contest" after he was spotted scratching at the surface by television cameras during the Proteas Test victory over Sri Lanka in Galle.

Protea ball tampering footage

The incident sparked a row between the South Africa and Sri Lanka boards, with the footage initially not broadcast but shown to umpires after play. Dale Steyn had run through the Sri Lankan batsmen with 5-50 on the way to a Test victory that saw the Proteas reclaim the world No.1 ranking from Australia.

Du Plessis was fined 50 per cent of his match fee for ball tampering in October 2013 during a Test in the UAE against Pakistan, where the batsman was found to have rubbed the ball over a zipper on his trouser pocket.

Match referee David Boon said at the time the ball-tampering charge was warranted for Du Plessis, but also that it "was not part of a deliberate and/or prolonged attempt to unfairly manipulate the condition of the ball".

The Proteas faced further ball-tampering controversy in February this year when Australia batsman David Warner suggested wicketkeeper AB de Villiers was roughing the ball with his gloves following a Test defeat in Port Elizabeth.

Warner was sanctioned by the ICC and later apologised for the outburst he admitted “probably wasn’t the smartest thing, and I regret saying that”.

Pikoli's comments come as national coach Russell Domingo had his contract extended until March 2016.

CSA chief executive Haroon Lorgat said the extension would give the Proteas more certainty in their ICC Cricket World Cup preparations. Domingo's contract had been due to expire at the end of the World Cup but has now been extended to April 2016, along with team manager Mohammed Moosajee.

"We're very satisfied with the performance of the head coach and manager, in particular during this time of transition with great players retiring over the last couple of years," said Lorgat.

"It has been seamless and the board was very impressed by the way the team grew back to No.1 in Tests and has migrated up the rankings in ODIs as well.

"Our focus is now on the World Cup and the team has progressed very well. We knew their prowess in Test cricket, but Russell is building a very competitive team in ODIs as well."