On Four Corners this week we investigate how the Perth Mint may have been used to move millions of dollars around the world.The Perth Mint, which is owned by the WA government, sells $20 billion of gold annually and is one of the world's biggest gold refiners. This makes it a very large business and one that should be acutely aware of its obligations to comply with Australia's anti-money laundering laws.We uncover major holes in its money laundering defences and how the historic institution has been singled out by law enforcement authorities.There's a notorious bikie who has bought gold with no background checks, and we put the WA Premier on the spot. We also delve into how clients of a tax haven bank were able to buy $25 million worth of precious metals from the Perth Mint.