He’s the financial equivalent of Ed Snowden and Julian Assange - a mild-mannered 29-year-old accountant facing jail for for lifting the lid on a global tax rort worth trillions.
It was in the spur of the moment decision when Antoine Deltour walked out of his dream job in Luxembourg armed with 28,000 documents he had secretly downloaded from his employer PriceWaterhouseCoopers.
These included confidential agreements between huge multinationals and Luxembourg - which is a tax haven - and exposed the true scale of the complex and secret web of international tax avoidance.
Some of the world’s biggest and most well-known companies were implicated, including 20 which were operating in Australia but were diverting revenue to overseas tax havens.
The explosive revelations became known as Lux Leaks and set off a chain reaction across Europe. Several countries have launched investigations into the companies involved.
But Deltour, and the French journalist who helped expose the story, are now facing jail on a string of serious charges because of what they did.
"The basic mechanism is just to move the profit, to shift the profit from high tax country to a low tax country," Deltour told Sunday Night in the interview to air August 16.
"Shift their profits to low tax countries like Luxembourg, also in other countries like Ireland and Netherlands and Cayman Islands."
The French journalist, Ed Perrin, said Deltour, was motivated to act because he sensed massive injustice.
"He saw something that was totally unacceptable and thought that this needed to be known," Perrin said.
"Did he know the risks? I think so, yeah."
The bombshell dropped by Deltour has led all the way back to Australia, with fresh revelations that in just one year, 10 companies operating in Australia shifted $31 billion to Singapore where they paid hardly any tax.
It’s money that Labor Senator Sam Dastyari says should be used to fund better schools, hospitals and roads but instead state and federal governments are looking to increase the GST.
"Well the figures I've seen say it's up to 30 billion dollars a year. $30 billion a year in tax revenue that's going out the door." Dastyari said.
"It’s a rort. It’s thievery. Australian families are getting ripped off. This is money that is being taken and stolen from us."
Tune in to Sunday Night August 16 at 7pm to see the full story.