Their advice bubbles up to the surface of government where ministers will either ignore them or follow their recommendations. Much of the work of running the nation is delegated to these agencies.

In short, public servants are hugely influential, more powerful than they appear, and yet also far less scrutable than many other government decision makers.

That makes questions over influence-peddling, conflicts of interest and corruption in the Australian Public Service fundamentally ones that concern the public. The integrity of government relies on every link in a long chain that extends all the way from junior agency staff to secretaries and ministers.

Any potential threats to that integrity deserve to be observed and tested. In the business of government, as in the private sector, gift giving is one such threat that, when abused, can expose decision-making and spending to corrupt behaviour.

Fairfax Media in the last two days has detailed many of the gifts public servants at major government departments have received since 2013. Nearly half a million dollars in gifts went to the Defence Department, many from weapons industry heavyweights.

Smaller but sizeable agencies charged with responsibilities that extend deep into the country's economy and communities have also received tens of thousands of dollars in items given by businesses, and foreign governments.

This isn't to say these gifts are evidence of wrong-doing, corruption or other misdemeanours. Many of the items received went to department social clubs and some were raffled off for charity. Public servants receive gifts when it would be rude to refuse them, or to hand them back. Departments interact with the private sector, moving in spheres where the corporate practice of gift-giving is the norm.

If there's nothing to hide, then it's also worth asking why government agencies are at pains to keep these gifts out of the public gaze. The details of gifts received by the government departments and reported by The Canberra Times over the last two days were available only in documents that were received through a long and involved freedom of information process.

Many departments rejected these applications for information. That's a sadly common roadblock for media. For the broader public, such obstacles are insurmountable barriers to fair scrutiny of government business.

Gifts are rife with potential abuse, and the government fails to recognise this in the way it hides them from the public. Those received by politicians are published. It's long past time for a public, accessible register of gifts received by public servants. Sensitive information, however that's defined, can be left out given reasonable justification and the opportunity for appeal.

Without a register at the fingertips of any interested member of the public, they will remain blind to a potentially distorting influence on a large and mostly hidden layer of government.