Melbourne's Crown Casino deliberately tampered with poker machines, and turned a blind eye to drug use and family violence, whistleblowers have alleged in damning evidence tabled in Federal Parliament.

Key points: Independent MP Andrew Wilkie tabled the former workers' allegations in Parliament

Independent MP Andrew Wilkie tabled the former workers' allegations in Parliament Crown allegedly deliberately disabled approved punting options on machines

Crown allegedly deliberately disabled approved punting options on machines Machine buttons were tampered with to allow illegal continuous play, the whistleblowers claim

Victoria's gambling regulator said it would "thoroughly investigate" claims made by three former Crown staff in video evidence tabled by independent MP Andrew Wilkie.

However, the men said the Victorian Commission for Gambling and Liquor Regulation (VCGLR) had previously discovered machines had been altered, but took no action except to order they be fixed.

Crown issued a statement rejecting the claims, which include allegations that:

Staff were told to remove betting options from pokies

Staff were told to remove betting options from pokies Crown regularly reset machines' memory to reduce returns to players

Crown regularly reset machines' memory to reduce returns to players Staff were instructed to use different player ID cards when processing transactions over $10,000, to avoid reporting to AUSTRAC, the national anti-money laundering agency

Staff were instructed to use different player ID cards when processing transactions over $10,000, to avoid reporting to AUSTRAC, the national anti-money laundering agency Punters soiled themselves while betting, and Crown provided them with clean clothes so they could continue gambling

Crown also ordered staff to "shave down" buttons on gaming machines to allow illegal continuous play on the machines, the former workers said.

State rules ban the practice of allowing a machine to spin without a user pressing a button for each spin.

But the former staff alleged they were instructed to use tools to shave down buttons on new machines to create space for punters to wedge something next to the buttons, so they could be held in place to keep the machines playing continuously.

Crown allegedly gave gamblers plastic items similar to guitar picks, featuring Crown's logo, which were jammed next to the buttons to hold them down.

Andrew Wilkie urged the federal and Victorian governments to investigate the claims. ( ABC News: Matt Roberts )

Mr Wilkie tabled the allegations, including a 30-minute recorded interview with the three whistleblowers, in what is believed to be the first case of video evidence being tabled in Federal Parliament.

The testimony was recorded as part of "PokieLeaks", a campaign launched by Mr Wilkie and fellow MP Nick Xenophon to expose illicit practices in the industry.

The explosive allegations come as the Victorian Government conducts its five-yearly review of Crown Casino's licence.

In a statement issued to the Australian Stock Exchange, Crown Resorts said it "rejects the allegations made today under parliamentary privilege … concerning the improper manipulation of poker machines and other illegal or improper conduct at Crown Casino in Melbourne".

"Crown calls on Mr Wilkie to immediately provide to the relevant authorities all information relating to the matters alleged."

Watchdog 'took no action' over machine tampering

The former workers said VCGLR inspectors did not act when they detected gaming machine technicians deliberately disabling several punting options on gaming machines.

"The worst case was where they [Crown] asked us to remove three out of the five play options,'' one man said.

On a standard poker machine there are a five betting line options — to play one, five, 10, 20 or 40 lines of wheels.

"They got rid of the five, 10, 20 [line options], so your options were one — which is betting two cents on the middle line — or 40, which is all the combinations," he said.

"So you basically remove betting options from the machine.

"We thought that was probably dodgy because we knew that the approval [of the machine by authorities] had come out with those extra buttons.

"The fact that they rolled that back a week later proves that that was not above board."

In the evidence, the former Crown employees said that when VCGLR inspectors saw the buttons were disabled, they immediately ordered the machines to be fixed but did not take further action.

In a statement, the VCGLR said it was working on improving its supervision of Crown.

"We take any claims of this type extremely seriously and they will be thoroughly investigated," the statement said.

"The VCGLR maintains constant oversight of the Melbourne casino and has taken active steps over the past 12 months to improve our level of supervision of the casino.

"This includes establishing a specialist dedicated casino team."

Crown allegedly gave gamblers guitar picks, which they used to jam into buttons on pokies. ( ABC News: Jane Cowan )

'Remove the wife, so he can keep gambling'

In February, Victoria's auditor-general warned that the VCGLR's compliance division "has not applied a level of focus on the casino that reflects its status and risk as the largest gaming venue in the state".

The auditor-general's report said also said areas of risk, such as money laundering, were not getting sufficient attention.

The former staff also alleged Crown put the most high-yielding poker machines in the highest traffic position in the casino during peak periods, and frequently reset pokies' RAM (memory) to manipulate the returns to players.

Under return-to-player guidelines in Victoria, pokies are required to return 85 per cent of the overall money gambled on each individual machine to players, allowing the rest to be kept as profit.

According to Responsible Gambling Victoria, it takes millions of games for a machine to reach its return rate, so the amount actually returned to players in any one session, day or week can vary significantly.

The former workers also said staff were instructed to cover up incidents of family violence and not alert police.

"It was more a matter of 'let's calm the situation down'. So you remove the wife, so he can then come back to the gambling,'' one said.

Sorry, this video has expired PokieLeaks blurred the video and distorted voices to hide the former workers' identities

'Misbehaviour' goes beyond Crown: Wilkie

Mr Wilkie called on the federal and state governments, as well as regulators, to investigate.

"Many laws have possibly been broken and the truth will not be uncovered without a parliamentary inquiry, as well as investigations by law enforcement and regulatory agencies," he said.

"Although the allegations focus on Crown in Melbourne, they also suggest a broader pattern of misbehaviour in the poker machine industry.

"That, obviously, has grave implications for people right around Australia."

Mr Wilkie said it was shocking regulators had turned a blind eye to the practices at Crown.

"I'm horrified to recount that the Victorian Commission for Gaming and Liquor Regulation has allegedly done nothing to stop this shocking criminal misconduct," he said.

Victorian Premier Daniel Andrews said the allegations should be taken seriously by the state regulator and Crown Casino.

"There are rules there, they should be followed," he told the ABC's Statewide Drive program.

"We don't want predatory behaviour, we don't want people doing the wrong thing.

"Part of having an independent watchdog … that's a recognition that probity is very important, standards and confidence are very important and I am equally confident that the regulator will do their job."

The Victorian Greens' gambling spokeswoman, Colleen Hartland, said Crown should not be allowed to continue operating poker machines until an independent audit is done.