Duluk was last month acquitted of a basic assault charge against SA Best MLC Connie Bonaros, but his political career remained in limbo after Marshall declared he “would expect the Parliamentary Investigation to continue”.

That inquiry, instigated by former Speaker Vincent Tarzia in January 2020 and conducted by Paul Hocking of Reynella-based Quark and Associates, was put on ice when police laid charges against Duluk.

Marshall noted at the time that the decision rested with current Speaker Josh Teague – who today declared he would not recommence the stalled investigation.

“I do not intend further to undertake investigations into the matter,” Teague told parliament.

“As the Speaker [Tarzia] said in February 2020, and I reiterate now, there is nothing preventing any aggrieved person from making a complaint to any relevant body, at any time, or for the house to adopt a course of action it thinks is appropriate further to deal with the matter.”

Teague, a practising lawyer before entering parliament, noted that Tarzia’s “fact-finding exercise” was intended “to find out particulars of what took place concerning alleged conduct of the member for Waite at a Christmas party held in the corridors of parliament house during the afternoon of 13 December 2019”.

“On 5 February 2020, the Speaker advised the House that the reason for embarking upon the fact-finding exercise was the unsatisfactory circumstance that an allegation of harassment by one member against another was at that time beyond the jurisdiction of the Equal Opportunity Commissioner,” he said.

“The Speaker at that time also alerted to the possibility of other investigatory and or enforcement agencies, including SA Police, acting on a complaint or indeed that the House might adopt a course of action as considered appropriate to deal with the matter.”

Teague noted that a police investigation subsequently did commence, which “resulted in the Member for Waite being charged with and subsequently tried for assault against the Hon. Connie Bonaros MLC”.

He said Magistrate John Wells’ judgement spelled out the facts relevant to the inquiry, adding that “the court having made those findings of fact, it is not for the Speaker to gainsay those matters”.

“In the circumstances, the matter the subject of the Speaker’s investigation is therefore overtaken by the police investigation and completed by the subsequent judicial process,” he said.

Teague insisted it was “clear that the only role for the Presiding Member in relation to complaints to the [Equal Opportunity] Commissioner arises in circumstances where a matter of privilege is raised”.

“In this case, I am not aware of any such issue having been raised,” he said.

“Nor is it an ideal situation for the Speaker to undertake the work of an investigator – far from it.

“It places the Speaker in an invidious position.

“The Presiding Member is not a judge and, more particularly, does not sit in judgement of members.”

In a statement early this afternoon, Duluk said he “welcomes the ruling of the Speaker today, and once again put on the record my personal apology and remorse for my behaviour on the evening some 20 months ago”.

“I know that daily, I have taken positive steps to reflect and improve as a person,” he said.

InDaily has sought comment from Marshall and Bonaros.

Earlier today, Marshall said he had not spoken to Teague about his decision and did not know what he had decided.

“I think it would be completely inappropriate for me to speak to the Speaker [about this]… he is independent and needs to make his own decision,” he said.

Later, in Question Time, Marshall responded to Opposition questions on the matter my saying Dulkuk’s behaviour at the drinks event was “completely unacceptable”.

However he said his party membership was “a matter for the state executive of the Liberal Party” – of which he is a member – and declared he would not canvass party decisions publicly.

Teague’s determination will force the Liberal Party to fast-track a decision about whether to readmit the exiled MP to the party-room – a problematic conundrum given Marshall has previously said publicly that he had become aware of “further allegations [that] were not brought to my attention by Mr Duluk”.

“The type of behaviour that has been publicly canvassed is completely unacceptable and falls well short of the standards expected of all Members of Parliament,” Marshall said last year.

Duluk’s seat of Waite is also the centre of political unrest, with a majority of his local State Electorate Conference backing the incumbent, while a moderate-backed coterie has sought to establish a new branch in the electorate which could presage a preselection challenge.

The defeat of Duluk’s conservative faction at the weekend Liberal AGM makes it unlikely he will gain sufficient support in the governing state executive, with one moderate telling InDaily yesterday they would be “shocked” if he was endorsed as a Liberal candidate.

However, he has long maintained he intends to run again in Waite, and is expected to gain significant support from local party members if he does so as an independent.

Labor’s deputy leader Susan Close said in a statement Teague’s decision was “a humiliating repudiation for Steven Marshall”.

“The ball is now firmly in Steven Marshall’s court – is Duluk in the Liberal Party or not?” she said.

“Steven Marshall has previously said Sam Duluk’s position in the party is untenable… Steven Marshall is the leader of the Liberal Party and a member of the party’s State Executive – he cannot handball responsibility, this is very much a matter for him.”

Greens MLC Tammy Franks, who was present at the Christmas drinks function and has reiterated calls for the Speaker to resume the stalled investigation, told InDaily today: “I’m surprised that the Speaker hasn’t resumed the inquiry, given it was focussed on more than the one incident that was taken to court as a basic assault charge.”

She said she would say more about the matter under parliamentary privilege tomorrow when she speaks to her previously-moved motion asking why the inquiry had not been resumed.