Queensland's Attorney-General has announced the state's gaming regulator will investigate allegations of money laundering related to Star Entertainment Group.
The Sydney-based company operates casinos in Brisbane and the Gold Coast.
Attorney-General Shannon Fentiman said the regulator will work in conjuction with Queensland police and the anti-money laundering agency AUSTRAC.
It comes after similar inquires were announced in New South Wales, WA and Victoria.
The casino operator's shares dropped 23 per cent to $3.30 yesterday after allegations published in Nine's The Age and Sydney Morning Herald described "suspected money laundering, organised crime, large-scale fraud and foreign interference" enabled by The Star.
In a statement to the stock exchange, The Star described the media reports as "misleading".
In a statement, Ms Fentiman described the allegations as "very serious" and said she was following the Bergin Inquiry into Crown casino.
"The investigation will consider the appropriateness and effectiveness of Star's due diligence processes in relation to anti-money laundering and how the Star approaches exclusions to ensure people are excluded from all properties where appropriate," it read.
"The government will be considering the outcomes of the various inquiries carefully and will make any necessary changes to the regulatory framework."
The Star Sydney casino is currently being reviewed by the New South Wales Independent Liquor and Gaming Authority.