For many years Australia's largest company, BHP, has been gaming our tax system, and it has been involved in disputes with the ATO over unpaid taxes in excess of a billion dollars. BHP has been joined by other large multinationals like Rio Tinto and Chevron in fleecing the Australian taxpayer through the use of tax havens and tax shields such as Singapore. BHP's Singapore tax shield and other tax havens exist to smuggle profits out of Australia.

Last month BHP's status as one of Australia's largest tax evaders was laid bare by its settlement with the tax office on disputes which go back as far as 2003. The settlement confirms what BHP has repeatedly and publicly denied, that its Singapore marketing hub was used for tax evasion using transfer pricing. This settlement with the tax office was made possible by laws I passed in 2012 and 2013 as Australian Treasurer. Over our six years in government the Liberals opposed every measure introduced by Labor to close corporate tax loopholes, which had in themselves been opened up by previous Liberal governments. The laws that delivered the settlement were opposed by the current Prime Minister. But, thanks to the Labor Party, the full impact of these laws in the years ahead will return many billions of dollars back to the Australian taxpayer.

I first raised the issues at the core of the BHP settlement with the tax office in 2015. BHP's duplicity and hypocrisy in this matter was laid bare in the Senate tax inquiry of that year. The finding of the Senate inquiry gave BHP the chance to come clean, reform their practices and rejoin the majority of Australian businesses that do pay their fair share of tax. Sadly, they chose the path of concealment. Since then, at every turn BHP have continued to deny the true purpose of their dual structure, which it continued to defend aggressively in all its public statements. But now, in this agreement with the tax office, it has shut down. I said then that the full impact of their activities was yet to be realised. These laws were used in the 2017 Chevron judgement handed down by the Federal Court, which added $430 million to the budget bottom line. I said then, assuming conservatively that 10 per cent of corporate tax revenue over the forward estimates was lost to tax minimisation and evasion, that a minimum cumulative cost to the budget would have returned many, many billions of dollars.

At every stage since 2015, BHP have chosen to deny, obscure and mislead the public over their deliberate tax evasion. The settlement with the tax office confirms that more than $1 billion in tax and royalty revenue has been funnelled out of Australia over the past decade, contrary to BHP's public statements. Stunningly, in the 2017 BHP annual report they confirmed that their CEO was awarded a million-dollar bonus for enhancing BHP's tax and transparency reputation. BHP cannot claim to be transparent given their failure to outline numerous back payments to the tax office as a result of tax audits over a decade long. When global companies like BHP act this way they compromise the social contract and give a green light to others to go about minimising or evading their tax.

When the former chairman, Jac Nasser, retired and a new chairman, Ken MacKenzie, was appointed, BHP did have the opportunity to restore its reputation as 'The Big Australian' and shut down its Singapore marketing hub. Sadly, it did not take the opportunity and launched another misleading advertising campaign. As I said at that time, BHP was at risk of becoming known as 'the dishonest Australian'. Sadly, its announcement of the settlement with the tax office continues down that path.

The BHP board now has an opportunity to be honest and forthright with the Australian people and not hide behind a legal agreement. The board should provide a full and frank explanation of its role in aggressive transfer pricing and the ethical framework it will use in the future to re-establish trust with the authorities and the public. It should now come clean about the total amount of royalties it owes state governments as a result of deliberately understating their sales to related parties. Anything less than a full and frank statement about these matters leaves a cloud over the board's commitment to transparency.

Congratulations to the ATO staff, who pursued this matter doggedly, and to our pensioners, patients and students who all benefit from their hard work. I salute the hard work of the tax office. In the wash-up of this scandalous attempt to undermine the tax base, what has become evident is that some leaders of corporate conglomerates like BHP simply believe they are above the law.