The federal government has declined to release information backing up minister Stuart Robert’s claims about a controversial China trip.

The Prime Minister has asked the head of his department to determine whether Mr Robert breached ministerial standards by helping a friend and Liberal Party donor sign a deal in China.

Labor used question time on Tuesday to test whether Mr Robert’s claim that he had taken the trip in a personal capacity was reflected in his China visa application and outgoing passenger card.

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Immigration Minister Peter Dutton said he would not be inspecting Mr Robert’s passenger card as it would be a breach of privacy.

“I haven’t brought the passenger cards down to question time with me … nor would it be appropriate for me,” he said.

The passenger card, which is a legal document, has eight options as the “main reason for overseas travel”: convention, business, visiting friends or relatives, holiday, employment, education, exhibition and other.

Mr Robert told parliament he had undertaken the trip “in a personal capacity”, but would not say what he wrote on his passenger card or visa application.

“I am confident I have not acted inappropriately,” he said, adding he would assist the review commissioned by Mr Turnbull.

The minister also would not say whether he met with a Chinese vice minister on his trip.

Opposition Leader Bill Shorten said the issue was a test of Mr Turnbull’s judgment.

The PM said he had immediately referred the matter to his departmental secretary, which was the appropriate way of handling matters of ministerial standards.

“Due process, accountability, integrity – that is what we stand for and that is what we will deliver,” Mr Turnbull told parliament.

When he was assistant defence minister, Mr Robert flew to Beijing in August 2014 to be at a signing ceremony for Nimrod Resources, a company led by his close friend Paul Marks.

Mr Robert took personal leave, approved by then Prime Minister Tony Abbott’s office, and paid for the trip out of his own pocket.

He has declared a financial interest in companies associated with Mr Marks.

The ministerial code of conduct says a minister shall not “act as a consultant or adviser to a company business or other interests, whether paid or unpaid, or provide assistance to any such body, except as maybe appropriate in their official capacity as minister”.

The Australian Financial Review reported Mr Robert met China’s vice minister of land and resources, Wang Min, a day after he attended the signing ceremony.

A Chinese government website says the pair discussed Chinese mining investment in Australia.

“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,” shadow attorney-general Mark Dreyfus said.

Trade Minister Andrew Robb declined to say whether his department had assisted Nimrod Resources.

Asked whether ministerial meetings with foreign officials were usually flagged with her, Foreign Minister Julie Bishop said there was no general practice.

Cabinet Secretary Arthur Sinodinos said he didn’t believe Mr Robert had breached any standards “if he has acted in accordance with the terms under which he undertook the trip when it was approved”.

“The judgment that was made at the time that the leave was approved was that he would conduct himself in a way as to avoid any appearance of that sort of conflict of interest,” he told ABC radio on Tuesday.

—AAP