Disgraced NSW MP Daryl Maguire has formally resigned from parliament after he was caught up in a corruption scandal.

The NSW Speaker's office confirmed it received a resignation letter from the former Liberal member for Wagga Wagga and junior minister on Friday afternoon.

READ MORE NSW MP Daryl Maguire to resign amid corruption scandal

Mr Maguire had pledged to quit before MPs returned from the winter break on August 7 after he was embroiled in a corruption scandal.

His resignation comes three weeks after a corruption inquiry heard secret recordings of him discussing potential commissions with a local councillor from property deals with a wealthy Chinese developer.

On July 21, NSW Premier Gladys Berejiklian said she spoke with Mr Maguire, adding "he advised me of his intention to resign from parliament before parliament resumes."

Ms Berejiklian said that following her conversation with Mr Maguire, she spoke with deputy premier John Barilaro, and they'd agreed there would be a by-election in Mr Maguire's seat of Wagga Wagga.

"There will not be a three-cornered contest. The Liberal party's held that seat for half a century and the Liberal party has opened nominations," she said.