SA Libs want explanation from Koustantonis

South Australian treasurer Tom Koutsantonis has breached the spirit of the state's ministerial code of conduct, Premier Jay Weatherill says.

Mr Koutsantonis is likely to keep his job despite growing pressure from the state opposition for him to better explain his use of "foul, gutter" language in government meetings or resign.

Mr Weatherill told state parliament on Thursday the treasurer's conduct was the subject of an hour-long meeting during which he was told such behaviour could not continue.

"Whatever the strict legal application of the ministerial code of conduct, it's certainly not consistent with the spirit of the code of conduct and that's why the minister apologised and that's why he was reprimanded," the premier said.

"People need to conduct themselves with dignity and it (the behaviour) is inconsistent with that."

The treasurer's profanities were revealed in a report from the Independent Commissioner Against Corruption in relation to the controversial Gillman land deal.

Commissioner Bruce Lander said the treasurer swore multiple times and said "c***" during dealings with public servants.

Mr Koutsantonis apologised after the report was released on Wednesday for what he said was "conversational swearing", but denied using the "c" word.

"It is unacceptable to use that kind of language in a setting where there is a power imbalance between ministers and members of the public sector," he said.

"The truth is inappropriate language is simply that. It is inappropriate."

Rather than a breach of the spirit of the code of conduct, Opposition Leader Steven Marshall said the treasurer's conduct was a substantial breach.

"This goes well beyond some foul, gutter language," he said.

"We would like some answers, some explanation why he should keep his job as the treasurer of South Australia."