The International Cricket Council (ICC) dismissed on Thursday an appeal by South Africa batsman Herschelle Gibbs against a ban for making derogatory remarks about Pakistanis during the first Test in Centurion.
Gibbs will miss the third test against Pakistan, starting in Cape Town on Friday, a Twenty20 international and the first game in the five-match one-day series. An earlier ICC statement said Smith would miss the first two one-dayers.
ICC code of conduct commissioner Richie Benaud said in a statement the fact that the remarks had been picked up by a stump microphone did not invalidate the decision made by match referee Chris Broad to ban Gibbs.
"With the benefit of some experience, I am able to add that players, no matter where they may be, should always bear in mind that a microphone could be live," the former Australia captain said.
The 32-year-old Gibbs was banned for two tests after being found guilty of breaching the ICC's Code of Conduct at a disciplinary hearing conducted by Broad after the first test.
Gibbs lodged an appeal and played in the second test at Port Elizabeth, which Pakistan won by five wickets to level the series.
Gibbs had been due to face a Cricket South Africa disciplinary hearing chaired by Judge Mervyn King, but that was postponed to allow the appeal to be heard.
Benaud said rejecting the appeal did not mean Gibbs was a racist.
"At Chris Broad's hearing (Pakistan team manager) Talat Ali spoke about the offence the words used by Herschelle would give to the whole Pakistan nation. I am not surprised.
"(However), as an Appeals Commissioner and a person, I certainly do not consider Herschelle to be a racist and I take great exception to the suggestion, in the same way I believe Chris Broad would object (to suggestions his finding would do the same)."
The issue marred South Africa's victory in Centurion although captain Graeme Smith said the home players themselves had been subjected to abusive comments from Pakistan fans.
Benaud expressed surprise the home players did not draw the attention of the match officials.
"I find it extraordinary that apparently the umpires were never brought into the problem by the captain, or the players. Or by Mr Gibbs himself."
The ICC Code of Conduct Commissioner's decision is final and binding.
South Africa captain Graeme Smith said losing Gibbs for three matches was a huge blow and added he had mixed feelings about stump microphones.
"Stump mikes are part and parcel of the game," Smith told a news conference on Thursday. "There's a part of me that would like them turned down but there's a part of me that realises that cricket needs to compete with other sports in the world.
"I'm sure there are people who love to hear the battles and what's being said. It makes you more a part of the game, I guess."