Australian Prime Minister Malcolm Turnbull has been named as a former director in a company created by Mossack Fonseca, the Panamanian law firm that specializes in shell corporations that the world's economic elite use to hide their money from taxation.

Mr. Turnbull insists there had been "no suggestion of any impropriety whatsoever" regarding the documents showing he was the former director of a company called Star Technology Systems Limited in the 1990s.  It began its life as a British Virgin Islands company set up to develop a $20 billion Siberian gold mine called Sukhoi Log.  Turnbull's friend and ally former NSW premier Neville Wran was also listed as a director.  Both men pulled out after a short time. 

"The company concerned was a wholly owned subsidiary of a publicly listed Australian company," PM Turnbull told reporters.  "So an ASX listed company of which Neville Wran and I were both directors for about two years," he added.

Opposition leader Bill Shorten said the PM's comments do not constitute a "full explanation".  Labor campaign spokeswoman Penny Wong echoed that call for Mr. Turnbull to be more forthcoming:

"How many other companies was he involved in which were established in tax havens?" Ms. Wong asked.  "How many other companies was he involved in that Mossack Fonseca was involved with?"

She continued, "He should be very upfront in answering questions about what he did or didn’t know about the activities of this company in relation to the Siberian goldmine."