Rugby league legend Andrew Johns has joined former jockey Allan Robinson in agreeing to appear

 Rugby league legend Andrew Johns has joined former jockey Allan Robinson in agreeing to appear at the Racing NSW inquiry into the feud between trainer Gai Waterhouse and owner John Singleton, reports ABC News.

It says: Johns, Robinson and brothel owner Eddie Hayson were the key figures absent from Monday's stewards inquiry involving Singleton and the Waterhouses over the performance of top mare More Joyous in the All Aged Stakes at Randwick last month.

Racing NSW chief steward Ray Murrihy said the trio were the missing link in the evidence presented before the inquiry was adjourned.

Robinson's lawyer Chris Murphy advised on Twitter on Tuesday morning that his client would attend subject to a medical clearance.

Johns's lawyer Colin Love later advised stewards of his client's decision to also attend the hearing when it reconvenes.

The former Newcastle Knights star had already been interviewed by Racing NSW's chief investigator Nathan Hayward and signed a detailed statement that was tendered on Monday.

Stewards have given Hayson until Friday to decide whether he will appear at the inquiry, which is expected to resume next week.

Johns, Robinson and Hayson are all reported to have been aware of information passed on by Tom Waterhouse that More Joyous was "off" heading into the All Aged in which the horse ran second last.

Singleton was fuming that he only found out about the alleged condition of the horse through Robinson before the race, prompting him to withdraw all his horses from Gai Waterhouse's stable.

The trainer told the inquiry that Singleton had ended a 15-year association based on "Chinese whispers" from a "trumped up little jockey, a brothel owner and a football player". (www.abc.net.au/news)