Embattled South Australian MP Sam Duluk has been banished from the parliamentary Liberal Party as investigations continue into his inappropriate behaviour at a pre-Christmas party.
Police confirmed on Friday they are investigating an allegation of basic assault against Mr Duluk.
Premier Steven Marshall said further allegations regarding incidents involving Mr Duluk have also been brought to his attention.
"This new information, combined with reports of a police investigation into Mr Duluk's behaviour, renders his position in the Liberal Parliamentary Party untenable," Mr Marshall said in a statement.
"Accordingly, I have advised Mr Duluk that he is no longer to participate in any meetings of the Liberal Parliamentary Party."
Mr Duluk came under fire after he allegedly slapped SA-BEST upper house member Connie Bonaros on the buttocks at the Christmas party held at Parliament House on December 13.
He is also accused of sending her unwanted text messages.
Ms Bonaros declined to comment on the police investigation.
Further concerns were raised over Mr Duluk's behaviour at the same event, including suggestions he made homophobic and racist comments.
Mr Duluk apologised both publicly and directly to Ms Bonaros, and quit his lead role on a parliamentary committee last month.
He told state parliament last week he deeply regretted his behaviour at the Christmas event and that it caused offence and distress to others.
"My behaviour on that evening was not consistent with my character and values," he said.
"I take full responsibility for my actions on that night."
Parliamentary Speaker Vincent Tarzia has also instigated an independent investigation into Mr Duluk's conduct but conceded recently he had no power to impose any sanctions.
A report from that investigation is due to be finalised soon.
Mr Marshall reiterated on Friday that he regarded Mr Duluk's alleged behaviour completely unacceptable and said it fell well short of the standards expected of all members of parliament.
But he said the MP's wider Liberal Party membership was a matter for the party's state executive.
Deputy Labor leader Susan Close said the evidence stacking up against Mr Duluk meant he should consider no longer being a member of parliament.
"This has been going on for more than two months. The premier could have dealt with this when it happened," Ms Close said.