Warner had reacted on his twitter page to a critical article on the Indian Premier League, followed by sensational spot-fixing scandal.
Sydney: Australian batsman David Warner was Wednesday found guilty of breaching Cricket Australia's code of behaviour over a Twitter tirade at two journalists and fined Aus$5,750 (US$5,608).
Story first published on: Wednesday, 22 May 2013 16:34
Cricket Australia said the explosive opener had pleaded guilty at the hearing late Wednesday and the fine was the maximum financial penalty for a first offence under its code of behaviour.
It said its senior code of behaviour commissioner, Justice Gordon Lewis, had found Warner guilty of breaching rule 6 which addresses 'unbecoming behaviour', over Twitter comments made by the 26-year-old at the weekend.
"In hindsight, clearly I let my frustrations get the better of me and posted some inappropriate tweets last weekend," Warner said in a statement after the adjudication.
Warner was called before the hearing after a heated social media tirade against two of the country's top cricket writers after he took exception to a story in Sydney's Daily Telegraph critical of the Indian Premier League.
The IPL tournament, in which the Australian was playing for the Delhi Daredevils, has been rocked by accusations of spot-fixing against three players, including Indian Test paceman Shanthakumaran Sreesanth and the story was illustrated with a picture of Warner.
After posting a tweet with expletives aimed at journalist Robert Craddock, urging him to "get a real job", Warner took issue with Craddock's News Ltd colleague Malcolm Conn in abusive tweets that sparked a back-and-forth exchange.
"While I disagreed with the story and my image being used alongside the story, I could have chosen my words better and I apologise for any offence that my language may have caused," Warner said Wednesday.
"I'll continue to have honest conversations with all my followers and I will be mindful of the language I use in future."
Earlier, skipper Michael Clarke threw his support behind Warner, saying he could still captain Australia despite the disciplinary hearing.
Clarke said Warner had apologised and learned from the incident.
"He's apologised and made it very clear it was unacceptable," the skipper said ahead of his weekend departure to England for the Champions Trophy and the Ashes series.
"I look forward to having Davey home and having him around the Australian cricket team," he added.
"He's a great man and I love playing cricket with him and I'm really confident that if he continues to grow as he has done over the past four or five years there's no reason, in my opinion, why he hasn't got the potential to captain Australia one day."
On Tuesday, Cricket Australia said it had no immediate plan to curb the use of social media by players, but suggested it could happen in the future.