Cape Town - Proteas coach Ottis Gibson has leaped to Quinton de Kock's defence, maintaining his innocence in the much publicised altercation with Australia's David Warner.

De Kock was charged by the International Cricket Council (ICC) on Tuesday following the pair's off-field confrontation during the first Test at Kingsmead.

CCTV footage showed Warner turning on De Kock as the players walked up a narrow staircase leading to the dressing rooms at the start of the tea interval at Kingsmead.

WATCH: Warner swears at De Kock before bust-up

Reports indicated that the Australians got personal with De Kock with Afrikaans website Netwerk24 stating that De Kock was labelled as a "bush pig" by the Australians.

In the video released by Fox News in Australia, Warner can be seen and heard calling De Kock a "f***ing sook".

On Wednesday, Warner escaped a ban and was subsequently fined 75 percent (R160 000) of his match fee and given three demerit points.

Meanwhile, De Kock appealed his level 1 charge and will face an ICC hearing on Wednesday evening.

In the build-up to the second Test in Port Elizabeth, Gibson protested De Kock's innocence lamenting that the Proteas wicket-keeper batsman was not aggressive.

"We're appealing the level 1 because we don't think Quinny did anything. Quinny wasn't aggressive, I think you saw some of the footage that showed Quinny walking up the stairs and someone else being restrained and Quinny gets a level 1, how does that seem fair?" Gibson told reporters on Wednesday at St. George's Park.

"If they (umpires) hear things on the field, they should clamp down on it. It becomes unfortunate when everybody else hears stuff and the match officials say they haven't heard anything. They are there to do a job and they must do their job.

"Quinny would not have said anything had something not been said to him in the first place. But I wasn't out there, Faf was there and probably knew what was said," said Gibson.

The 25-year-old faces a level 1 charge, which also relates to "conduct that brings the game into disrepute" with a fine being the most severe punishment.

Gibson insisted that De Kock's level 1 charge was unfair and insinuated that it was the Australians that crossed the line.

"But there's one guy walking up the stairs going back to his dressing room, there's another guy having to be restrained. If I am walking, trying to get back to my dressing room and somebody is being restrained, how can you fine me for something?" said Gibson.

"They are saying they didn't cross the line, but where is the line? So you were saying stuff, but 'oh no, we didn't cross the line, we got very close to the line but didn't cross the line.' Whose line is it?"

"Can you say whatever you can and then when something is said back to you then it's offensive? You didn’t tell us where the line was. Let's be clear where the line is," added Gibson.

"I think everybody just needs to focus on cricket. Calm down and get back to cricket."

The second Test between South Africa and Australia gets underway on Friday at St. George's Park at 10:00.