The Perth Mint is facing fresh concerns about the quality of its background checks as it is facing a potential $9 billion recall of gold bars after selling bullion that had been dilated with silver to China, and then covering it up. 

It comes after allegations a notorious bikie was able to purchase $27,000 worth of gold, with just his drivers license. 

The State Opposition says the government needs to accept responsibility for compliance failures at Perth Mint.

"They're flogging false gold to the Chinese so how do you know the gold you've purchased is real?" Millsy said on 6PR Breakfast.