Queensland Opposition Leader Tim Nicholls has flatly denied claims of a secret deal between the Liberal National Party and One Nation.

The ABC's Four Corners program on Monday night aired what it said was a recording of Pauline Hanson's chief of staff James Ashby saying he'd struck a deal with Mr Nicholls' chief of staff for the two conservative parties to rein in attacks on each other.

Senator Pauline Hanson and her chief of staff James Ashby. Credit:Andrew Meares

"I have an agreement with the Liberal National Party, I've made a commitment to them ... that we will not go out there and slag them off for the sake of slagging them off," Mr Ashby said during the secretly recorded phone hook-up.

"But I reminded him that if he doesn't (honour) the agreement, we'll have plenty of ammunition on their candidates, which pulled his head in."