Button blanking pokies could cost Crown

Crown might have broken the law and could lose it's licence for "blanking buttons" on poker machines at its Melbourne casino.

Victoria's gambling regulator has launched disciplinary proceedings following an investigation over claims of tampering, which were tabled in federal parliament in 2017.

The watchdog has told Crown it might have breached the gambling act when it trialled blanking buttons - essentially reducing options - on a number of poker machines over a three-week period.

Crown denies it has breached the law.

"The commission has commenced disciplinary proceedings against the casino operator," a spokeswoman for the Victorian Commission for Gambling and Liquor Regulation said in a statement on Monday.

"These proceedings relate to the use of blanking of buttons on certain electronic gaming machines on the casino floor."

Crown, in a statement to the stockmarket, said the matter related to 17 of the casino's 2,628 machines during a period between March and April.

"The commission's view is that the trial involved varying a gaming machine type and certain games in a manner that required the commission's prior approval," the company wrote.

"Crown Melbourne's position is that the trial did not require prior approval, and therefore there has been no contravention of the (Gambling Regulation Act)."

The commission is now considering a response from Crown.

If it decides there are grounds for further action, Crown could have its casino licence cancelled or suspended, or may face a fine.

Independent MP Andrew Wilkie in 2017 aired whisteblower allegations of machine tampering, which have been strongly denied by Crown.

He welcomed the developments on Monday.

"The casino obviously has a case to answer about the blanking of buttons and I'm sure that the truth will come out when the commission finalises its inquiries," Mr Wilkie said.

The commission said an investigation was underway before Mr Wilkie tabled the claims in parliament.