The Australian Taxation Office is preparing to go to war with companies­ involved in alleged complex gold scams that have cost taxpayers more than $700 million in lost GST revenues, pledging to leave “no stone unturned” as it seeks to claw back funds and unravel­ the long-running saga.

The alleged fraud being targeted by the ATO involved criminal syndicates buying and selling gold and pocketing GST refunds by exploiting­ the different tax treatment of gold, depending on whether it was in scrap or bullion form.

Pure gold is treated by the ATO as currency, and it cannot be sold with the addition of GST, whereas scrap gold attracts a 10 per cent premium.