Crown Melbourne is facing fresh sanctions over alleged exchanges of blank cheques for gambling chips.
The Victorian Gambling and Casino Control Commission on Thursday issued a notice to the casino operator, compelling it to provide any relevant information to the regulator.
It is the third disciplinary proceeding brought against Crown Melbourne following last year's royal commission.
The inquiry found the operator had breached the Casino Control Act by exchanging blank cheques for gambling chips.
Patrons also received chips after providing bank cheques that were made out to themselves, the hearing was told.
"These restrictions are vital because they protect patrons from gambling beyond their means and guard the Melbourne casino against criminal influence and exploitation," commission chair Fran Thorn said in a statement on Thursday.
Crown could receive a fine up to $100 million, have its casino licence varied or be issued a letter of censure.
The casino operator says it will fully cooperate with the regulator's proceedings.
"Crown has undertaken comprehensive reforms across the business to ensure that serious compliance failures do not happen in the future," a Crown spokesperson told AAP in a statement.
"Crown's priority remains the delivery of its reform and remediation program to deliver a safe and responsible gaming environment."