An explosive wave of fraud that has shaken the Tax Office’s GST system had been building for months before accountants began to notice early last year. By then it was everywhere and no one wanted to talk about it.

“I started seeing it through the office about March of 2022, a few people came in with business files with the ATO – these really large credits going out, big, big credits, unusual credits,” a western Sydney accountant told The Australian Financial Review.