The Perth Mint has been forced to replace its long-standing auditor and overhaul its ethical sourcing regime but was not stripped of its London accreditation despite revelations it purchased tainted gold from a convicted killer in Papua New Guinea.

The decision by the London Bullion Market Association, the world's largest precious metals exchange, allows the Mint to remain on the so-called "good delivery list", a crucial rating for banks and fund managers investing in precious metals.