A scandal is brewing in the backyard of Malcolm Turnbull government. This is about Human Resources Minister Stuart Robert’s private trip to China in 2014. The opposition Labour Party has called for a probe into the trip and an answer from the minister.

According to Labor, it was actually the minister’s personal business trip. The opposition charge is that the minister misused the official privilege and contravened rules in furthering his personal and business gains.

The trip of August 2014 was made when he was Assistant Defence Minister in Tony Abbott’s government. Robert visited China after taking leave and paid the trip’s expenses from his packet.  Labor has challenged the perception that Robert travelled to Beijing in his “private capacity” for attending the signing ceremony between Paul Marks’s Nimrod Resources and China’s Minmetals.

The “private visit” became a controversy after Minmetals in a press release claimed that Robert attended the ceremony on behalf of the Australian government and made a speech. Labor alleged that Robert’s China trip was to seal the mining deal between a Liberal Party donor and government company in China, reports The Sydney Morning Herald.

But Foreign Affairs Minister Julie Bishop justified Robert’s trip and said it was “perfectly acceptable.” Labor also cited his “close friendship with Marks”, who is a donor to the Liberal Party. The opposition party alleged that the minister had a private interest as he holds shares in Marks’ Evolution mining company. That is also mentioned in the parliamentary records.

Flaying Robert for “appalling lack of judgment” and conflict of interest, Labor defence spokesman Stephen Conroy accused the minister of having misused public office for making personal gains.

“There is a prima facie case of a breach of the ministerial code of conduct,” he told reporters in Canberra on Monday. “Every minister knows you are not allowed to use your office for your personal benefit,” Conroy noted

Conroy urged immediate action from Prime Minister Malcolm Turnbull with a full explanation from Robert. He also wanted the transcript of Robert’s remarks at the ceremony made public. The Labor leader urged Turnbull to sack the minister, if his explanation is not satisfactory.

However, Cabinet minister Simon Birmingham played down the controversy, reports News.com.au. “I’m sure Mr Robert will have something to say in terms of making sure that it is clearly understood that it was a private capacity and the way in which that occurred,” he told Sky News.