Gladys Berejiklian knew that disgraced former MP Daryl Maguire, with whom she was in a relationship, stood to make hundreds of thousands of dollars on a Badgerys Creek land deal that he lobbied her office to intervene in.

Appearing before the Independent Commission Against Corruption on Monday, the NSW premier revealed she was in a “a close personal relationship” with Maguire when he was forced to resign from parliament amid a corruption scandal in 2018.

During a morning of stunning revelations, the inquiry heard intercepted phone calls in which Maguire told Berejiklian that he potentially stood to make hundreds of thousands of dollars if land owned by the racing heir Louise Waterhouse near the site of the new Western Sydney airport was rezoned.

The payment would have been enough to pay off “about half” of his $1.5m personal debt, Maguire told Berejiklian in one phone call.

Berejiklian responded: “I don’t need to know about that bit”.

In a sometimes tense exchange with counsel assisting the inquiry, Scott Robertson, Berejiklian denied she had been trying to limit her knowledge of Maguire’s activities, saying she: “probably would have firstly not regarded it as interesting to me, it was not something I paid particular attention to”.

She said if she had felt there was “wrongdoing on the part of Mr Maguire” she would have reported it.

“If I did regard anything as a concern, I would have reported it or dealt with it, and I want to make that very clear,” she told the inquiry.

The inquiry has previously heard Maguire had been lobbying government officials on behalf of Waterhouse, and had given the racing heir access to Berejiklian’s direct email address.

Another intercepted phone call played on Monday revealed that Maguire told Berejiklian that Waterhouse was going to email her, saying she