SA Premier Jay Weatherill launches legal action against Liberal Party for defamation over radio advertisement

South Australian Premier Jay Weatherill has filed legal proceedings against the state division of the Liberal Party for defamation.

The claim, worth almost $30,000 plus court costs, relates to a radio advertisement the Liberal Party funded during last year's state election campaign.

The advertisement falsely claimed Mr Weatherill knew about a rape at a western suburbs school and was aired after the Debelle Royal Commission ruled Mr Weatherill had no knowledge of the matter.

Mr Weatherill said took the action because the Liberal Party failed to publish a retraction as was ordered by the Electoral Commissioner.

"It took me quite a long time to actually get a hold of it. It was running for sometime," he said.

"I then had to take it to my lawyers and get it analysed, then when we realised what had been said we then got on to the Liberal Party and they apologised.

"But the damage had been done by that point and these are very serious and nasty allegations."

Mr Weatherill said he would not be pursuing the woman who voiced the advertisement, independent child protection candidate Mel Calone.

"My interest is in the Liberal Party being held to account, not some woman who's been dragged into this poor thing," he said.

In a statement the Liberal Party said it had no contact with the Premier since the election and was yet to be served with court documents.

"During the state election campaign in March last year, the Premier indicated he may take legal action against the Liberal Party over a radio advertisement recorded and funded by the party," the statement said.

"We have had no contact from the Premier or his legal team about this issue in the subsequent 11 months and are yet to be served with court documents.

"At this stage, we are simply responding to media reports and will not be making any further comment."

Mr Weatherill is funding his own legal action.

A court date is yet to be listed.