Melbourne's Crown Casino has been banned from handing out special plastic picks used by punters to bypass poker machine rules because their use increases the harm from gambling, the industry's Victorian regulator has said.

Key points: Whistleblowers told the ABC in 2017 that Crown Casino was handing out plastic picks, which punters would jam into poker machine buttons

Whistleblowers told the ABC in 2017 that Crown Casino was handing out plastic picks, which punters would jam into poker machine buttons The gambling regulator has since determined the picks may increase the risk of gambling-related harm

The gambling regulator has since determined the picks may increase the risk of gambling-related harm Independent MP Andrew Wilkie called the regulator's decision not to issue any fines "pathetic"

Whistleblowers told the ABC in 2017 that Crown Casino was handing out specially branded plastic picks, which punters would jam into poker machine buttons.

The picks, similar to guitar picks, were jammed into the buttons, allowing the poker machine to play continuously.

Victorian rules require gamblers to press a button for each bet, which takes less than three seconds. This was designed as a harm-minimisation measure.

Three weeks ago, the Victorian Commission for Gambling and Liquor Regulation (VCGLR) quietly made public that Crown would be banned from handing out the picks.

No fines were issued.

"Following the investigation, the VCGLR has determined that the distribution and use of button picks may increase the risk of gambling-related harm and, as such, should not be permitted," the commission said.

The casino is also required to prevent the use of button picks.

The whistleblowers' revelations forced a probe after formal complaints from federal independent MP Andrew Wilkie to the commission, as well as outrage from gambling experts.

Crown said it had stopped handing out the picks before an investigation began. ( ABC News: Jane Cowan )

Pathetic response: Wilkie

The Tasmanian MP called the response from the commission "pathetic".

"Not only did the VCGLR take months to come to this conclusion when the evidence was right in front of them the whole time, but there has been no fines, no jail time — in fact no punitive action whatsoever," Mr Wilkie said.

"Instead Crown has just received a polite talking to and a 'don't do it again'."

He said it "beggars belief" that the regulator was unaware of the use of the picks.

In 2017, Crown was also accused of removing buttons that limit bet options from poker machines, to force higher bets. It denied the allegations.

But last year the gambling and entertainment giant was fined $300,000 by the gambling commission for removing betting options on several machines without approval.

Crown Casino told the investigation that it stopped handing out the button picks before the investigation began.

Crown has been contacted for comment.