The former High Court judge heading the Abbott government's $61 million royal commission into union corruption spent much of this year teaching law at Oxford University, as the inquiry went without a public hearing for nearly six months.
Commissioner Dyson Heydon taught the subject hearsay during Hilary term at Oxford, which runs from January to March. His last Oxford lecture was on March 12.
Oxford University confirmed Justice Heydon had taught there between January and March as a visiting professor at the faculty of law. The university is one of the most prestigious in the world, and graduate courses in law can cost students up to $50,000 a year in tuition fees.
A royal commission spokesman defended Justice Heydon's time at Oxford and said the inquiry had been operational since its interim report was delivered in mid December. Since then, police taskforces had been established in three states.
He said there had had been "numerous" private hearings through April.
The next public hearing is on April 27, nearly six months after the last one on November 13.
The spokesman confirmed Justice Heydon had been paid for signing legal documents as part of his commission work while at Oxford, but refused to say how much or how he was engaged.
The government has refused in Senate estimates to release details on how much Justice Heydon or his counsel assisting, Jeremy Stoljar, are being paid for their royal commission work.
But contracts on a government website show that Mr Stoljar was paid about $3.4 million in 2014. Law firm Minter Ellison was paid almost $17 million.
Opposition workplace relations spokesman Brendan O"Connor, said the delay in hearings exposed the commission's political agenda.
"After a year of spending tens of millions of taxpayers' money, it is clear the reason for this royal commission is more about attacking the government's political opponents than it is about fighting crime," he said.
"This six-month break in public proceedings, just like the government's imposed extension [of the inquiry], exposes the government's lies about its reasons for calling this inquiry."
ACTU president Ged Kearney said the royal commission was a "political witch hunt" and "nothing about the inquiry is surprising".
In December the Abbott government extended the royal commission for another year, to the end of 2015.
An 1817-page interim report by Justice Heydon made adverse findings against numerous current and former union officials. It recommended criminal charges against several Construction, Forestry, Mining and Energy Union officials including current Victorian secretary John Setka. It said the CFMEU acts in "wilful defiance of the law".
The interim report also raised concerns about the use and operation of union slush funds, including that they operate largely in secret, and have deficient or non-existent record keeping.
