Embattled Turnbull government minister Stuart Robert has refused to answer key questions about the secretive China trip that has put his frontbench future in doubt as it emerged he took representatives from Nimrod Resources - the Australian company run by his close friend Paul Marks - into his meeting with a Chinese minister.
The Human Services Minister is under heavy fire for his role in helping Mr Marks, also a Liberal Party donor, with a mining deal with the Chinese government-owned company Minmetals.
He claims he attended a signing ceremony in Beijing in August 2014 - when he was assistant defence minister under Tony Abbott - in a "personal capacity". But Minmetals has said he was there on behalf of the government and made an official speech.
Labor has accused Mr Robert - who owns shares in some of Mr Marks' other companies - of a conflict of interest and misuse of public office. The scandal deepened on Tuesday when it was revealed Mr Robert had a meeting with a Chinese government minister during the trip, which Labor says weakens his claim he was travelling on a personal basis.
Now a translation of a Chinese government webpage suggests people from Nimrod were at Mr Robert's meeting with Wang Min, China's vice-minister of land and resources, the day after the signing ceremony.
"Stuart Roberts (sic) said the Australian government welcomes Chinese company investment in mining exploration and development in Australia," the translated document says.
"He said that China Minmetals Corporation and Nimrod Resources have set up a joint technical committee, the sign of a new beginning.
"He is glad that the Ministry and Geological Survey Bureau officials, people from the China Minmetals Corporation and Australia Nimrod Resources attended the meeting today."
Mr Robert declined to comment on the revelation, which will raise fresh questions about the lengths he went to for Nimrod and Mr Marks.
Prime Minister Malcolm Turnbull has ordered the nation's top public servant - Department of Prime Minister and Cabinet boss Martin Parkinson - to investigate the affair.
Labor ramped up its question time attack on Tuesday but Mr Robert stood by his claim the trip was personal, with Sky News also reporting he travelled to China on a tourist visa.
"I am confident I have not acted inappropriately and as the PM said yesterday, this matter has been referred to the highest public servant in the land, Dr Martin Parkinson, for review. I will fully assist the secretary in his review," Mr Robert told Parliament.
But asked further questions - such as whether his outgoing passenger card or Chinese visa application reflected that he was travelling on a personal basis - Mr Robert refused to answer.
Mr Turnbull stands by his process.
"The government can't be criticised for being slow in reacting," the Prime Minister told Parliament.
"We have set in train the appropriate process, immediately [when] the matter came to light. The secretary will diligently look into the matter and he will provide me with advice and then I will make a decision."
Shadow attorney-general Mark Dreyfus said Mr Robert must explain himself.
"He's got to now make a full statement as to what it was he was doing in Beijing. It can't be both a trip for private purposes and a trip on which he met with a vice-minister in the Chinese government," Mr Dreyfus told reporters.
He also called on Mr Turnbull to show leadership on the issue: "Running for cover behind a departmental inquiry is simply not good enough."
But Defence Minister Marise Payne backed Mr Robert on Tuesday.
"I have complete confidence in the minister," she said.
Mr Robert describes himself a "close personal friend" of Mr Marks, who has donated $2 million to the Liberal Party in recent years.
The scandal comes only weeks after Mr Turnbull lost two ministers - Jamie Briggs and Mal Brough - to scandal.
