Child Support Agency bosses have spent the money despite knowing, since August 2011, that their public servants broke the law in the man's case and were on shaky legal ground from the beginning of the dispute. DHS has been ordered by the government's information watchdog to hand over a briefing it prepared for its minister, along with other documents, but the department has hired top-end lawyers Clayton Utz to fight the decision of the Australian Privacy Commissioner. Do you know more? Send your confidential tips to ps@canberratimes.com.au Throughout the three-year legal battle with the father, a determined litigant known simply as "DT" because of strict Family Court rules on identifying parties, Human Services have tried to resist handing over documents to the court and defied orders to release information to the Office of the Australian Information Commissioner. Transparency and accountability at Human Services, the government's largest department, has been under fire since a report by the Information Commissioner revealed an organisation obsessed with process, that preferred legalese to plain English and had increasingly lost sight of its duty to share information.

As of April this year, DHS had paid more than $500,000 to defend the DT case and refuses to say what has been spent since. The department refused this week to say how much taxpayers' money was being paid to Clayton Utz for the latest legal manoeuvre but a spokeswoman insisted the department was justified in another round of legal action to keep documents suppressed. "Matters are generally appealed to the Administrative Appeals Tribunal where the decision being appealed contains an error of fact or an error of law," the spokesman said. "As this matter is subject to ongoing litigation, the department will not be providing further comment at this time." Senator Xenophon has been trying to use Senate estimates to get answers on the spending on the case, but his questions have been taken on notice, with Human Services then refusing to answer, citing "confidentiality".