Scott Morrison has thrown his weight behind the embattled Gladys Berejiklian, ahead of Wednesday’s evidence to the Independent Commission Against Corruption from disgraced former MP Daryl Maguire, with whom she had a “close personal relationship” for five years.

Morrison said Berejiklian, who had been “a tremendous premier”, had his “absolute support”.

Maguire, former Liberal member for Wagga Wagga, is due to give evidence over two days.

Berejiklian was grilled for several hours on Monday at ICAC, which is investigating whether Maguire misused his parliamentary position for financial gain. Tapped phone conversations were played in which he talked to her about his efforts to broker deals for property developers, notably a sale of land owned by Louise Waterhouse near Badgerys Creek, from which he hoped to get a huge commission.

Berejiklian, who says she did nothing wrong and is not being investigated, told a news conference after her ICAC appearance that she had “stuffed up” her personal life.

She only severed her secret relationship with Maguire recently, despite his resignation from state parliament in 2018, after his property activities came to light in an earlier ICAC inquiry.

Morrison said Berejiklian had shown “a lot of courage” on Monday.

“But I also thought she showed a lot of humility, which is the Gladys I know.

"We’re all human. And particularly in those areas of our lives, and Gladys is an extremely private person, and a person of tremendous integrity. She’s a great friend. And I know she’s been getting many messages of support from her friends and colleagues and including from me … and Jenny.”

Morrison thanked state ministers “Dom Perrottet and Brad Hazzard and the whole team down there in the New South Wales government” for “getting in behind her.”

The last thing Morrison would want at the moment would be the removal of Berejiklian – he has repeatedly praised her government’s performance as the “gold standard” in handling the pandemic and highlighted NSW’s economic progress. So far there has been no sign of a move against her by colleagues and she has indicated her determination to tough out the scandal.

At ICAC on Tuesday Maggie Wang, a former business associate of Maguire, related what he had told her after his appearance at the earlier ICAC investigation. He had said words to the effect, “There’s been an unfortunate accident where my phones and iPad have been run over by a tractor”.