John Singleton says rugby league legend Andrew Johns was one of the two men who contacted him over the condition of his horse More Joyous that led to his spectacular falling out with his trainer Gai Waterhouse.

Singleton has accused Waterhouse's son, the bookmaker Tom Waterhouse, of telling people the champion racemare could not win the All Aged Stakes at Randwick last Saturday.

At a trackside inquiry on Saturday, Singleton refused to divulge the names of "trusted friends" who had told him Tom Waterhouse was saying there was a problem with More Joyous.

Johns on Tuesday released a statement dismissing claims Tom Waterhouse had tipped him off about the condition of More Joyous.

Retired jockey Allan Robinson said he spoke to Singleton but said it was not Johns who had told him about More Joyous' condition.

At the initial inquiry on Saturday, Singleton refused to divulge the names of "trusted friends" who had told him Tom Waterhouse was saying before the race there was a problem with More Joyous.

As a registered owner, he can be compelled to do so at the next stage of the inquiry.

But on Wednesday night, he broke his silence.

"Names have already been named so my reluctance to name names has been taken away by the names naming themselves," he told Channel Nine.

When asked if Johns and Robinson were those people, Singleton replied: "Yeah, they're both the people who rang me, yes."

Tom Waterhouse has denied the accusations and will front the reconvened inquiry next Monday.

It was revealed during Saturday's preliminary inquiry that More Joyous had been treated with antibiotics leading up to the All Aged but she had been cleared to run by two vets, including the one employed by Singleton.