SYDNEY (REUTERS) - Two ministers in Australian Prime Minister Malcolm Turnbull's government resigned on Tuesday (Dec 29), one of them standing down after a female public servant complained about his behaviour in a Hong Kong bar during a recent official visit.

Mr Jamie Briggs said he was resigning as Minister for Cities and the Built Environment after the unnamed woman raised concerns about his inappropriate behaviour towards her at a "popular and as it transpired very crowded bar" in the Chinese city and former British colony.

Mr Briggs, who was promoted to the front bench by Mr Turnbull earlier this year, said nothing illegal had been alleged, but declined to comment in detail about the incident.

"I've apologised directly to her but after careful reflection about the concerns she raised and the fact that I was at a bar late at night while on an overseas visit, I have concluded this behaviour has not met the particularly high standards for ministers," Mr Briggs told reporters in Adelaide.

Mr Turnbull said a second minister, Mr Mal Brough, was also standing aside while police investigate his role in revelations about a political rival that were leaked. "In offering to stand aside Mr Brough has done the right thing, recognising the importance of the government maintaining an unwavering focus on jobs, economic growth and national security," Mr Turnbull said in a statement.

The ministers' duties will be taken up by other ministers.

Mr Turnbull is riding high in opinion polls, with a Newspoll survey out on Tuesday (Dec 29) showing 61 per cent of voters preferred him as prime minister, versus 17 per cent for opposition Labor party leader Bill Shorten.