The More Joyous racing inquiry will resume on Monday but it is still unclear if brothel owner Eddie Hayson will appear.

While rugby league great Andrew Johns and former jockey Allan Robinson have both confirmed they will front the inquiry, Racing NSW are still waiting to hear from Hayson.

The trio have been identified as central figures in the inquiry which is investigating whether there was an issue which should have been reported with the John Singleton-owned, Gai Waterhouse-trained More Joyous before she ran second last in the All Aged Stakes last Saturday week.

Robinson rang Singleton on race day to tell him that Johns had been told by Waterhouse's bookmaker son Tom that More Joyous could not win.

Stewards held an at-times heated inquiry on Monday when they heard evidence from many of the main parties but neither Johns nor Robinson were in attendance and the hearing was adjourned.

Deputy chief steward Greg Rudolph said they hoped the presence of Johns and Robinson on Monday would provide clarity about their conversations on All Aged Stakes day.

"Mr Singleton, Mrs Waterhouse, Tom Waterhouse and the stewards will also have the opportunity to question them and the stewards will have the opportunity to see, after all the evidence is taken, if any charges will be issued in respect to any party," Rudolph said.

Rudolph confirmed that stewards had attempted to contact Hayson both directly and through his legal team on Wednesday without response.

The inquiry will resume at 10am (AEST) on Monday.