A fourth Crown Casino whistleblower has come forward with allegations of poker machine tampering, federal parliament has been told.
Independent MP Andrew Wilkie asked Prime Minister Malcolm Turnbull in parliament on Tuesday whether he would support a parliamentary inquiry into Crown.
Mr Wilkie said the fourth whistleblower had produced names of Crown staff who told him to modify machines, which had been referred to police.
However the whistleblower feared for his safety and had asked for a parliamentary inquiry to enable the public to learn the truth.
Mr Turnbull said police, gambling regulators, and money movement watchdog AUSTRAC were the most appropriate bodies to investigate the allegations.
"Those agencies have the necessary powers, extensive powers and, indeed, powers far greater than a parliamentary committee," Mr Turnbull said.
The Victorian Commission for Gambling and Liquor Regulation is investigating allegations already raised by Mr Wilkie, and AUSTRAC is examining claims of money laundering.
Crown Resorts has accused Mr Wilkie of playing political games by making his allegations.
In full-page newspaper advertisements Crown emphatically rejects the claims.
Apart from the machine-tampering claims, it is alleged Crown allowed the use of illicit drugs at the casino, covered up domestic violence, and avoided scrutiny by AUSTRAC of transactions over $10,000.
