Some of the more than 83,000 contracts let by the military in that period, obtained from the Department of Finance and Deregulation’s records, go beyond what members of the public might find acceptable. Stuff They include: More than $1.4billion on travel that includes the use of private Learjets, first-class airfares and accommodation in five-star hotels and resorts all over the world. Original oil paintings and hand-made office furniture, including $40,000 on a series of custom-designed Chesterfield leather couches.

Taxpayer-funded membership of exclusive clubs, the use of personal trainers, and subsidised overseas sporting trips. Almost $200million on marketing-related expenses, which largely focused on trying to recruit and retain more soldiers. This includes a $1.7million bill over four years to accommodate trainee recruits in hotel rooms in Sydney and Melbourne, and a separate $160,000 to fly school-age army cadets to overseas camps including in the United States, Germany and the Cayman Islands. The Herald has also discovered a number of phantom contracts that have mystified the companies to which they were meant to have been awarded, raising questions about the accounting rigour within the $26-billion-a-year agency. Taxpayers have funded games of skirmish, horse-riding adventure trips and sailing voyages, and $20million for leadership-oriented consultancies that include executive coaching and team-building workshops. More than $18,000 was paid just to cover what official documents term "incidentals" on a Defence employee rugby trip to Europe, and another $25,000 was spent on memberships to exclusive golf clubs in Canberra and Singapore.

The examination reflects the sheer scale of the department's budget and the extent to which Defence has successfully quarantined its funding from the typical budget pressures applied to other Commonwealth agencies. This is despite review after review warning that the department's spending was out of control. Thirteen years ago, a top-level report recommended urgent reform of the department, identifying up to $1billion a year that could be saved. The Pappas review, in 2008, found the agency was wasting $1.8billion a year. As much as $518million a year could be cut from the Defence budget, it said, in building maintenance, professional services, training, advertising, health and travel.

Last year, the federal government said Defence had to find $20billion worth of efficiencies and savings by 2019 to afford the new technologies needed to defend against threats. The government's strategic outlook document warned: "The Defence organisation needs fundamental reform." But the Herald's examination raises new questions about the accountability of a department that has become the single biggest spender of taxpayer dollars. Over the four years examined, the two biggest beneficiaries of the Defence budget were the US government's foreign military sales program and Australian Aerospace, a subsidiary of the European Aeronautic, Defence and Space Company. Loading

Combined, these two foreign government contractors received more than $5.2billion, or more than 10 per cent of all contracts published by the department.