The racing career of More Joyous may be over in the aftermath of the inquiry into her failure in last month's All Aged Stakes.

The multiple Group One winning mare was one of several horses taken from the Gai Waterhouse stable by owner John Singleton, the rest being mostly unraced two-year-olds.

Singleton publicly sacked Waterhouse after the All Aged Stakes on April 27 amid accusations her bookmaker son Tom had said she could not win.

Tom Waterhouse was exonerated at Monday's inquiry, Singleton pleaded guilty to conduct prejudicial to racing while the hearing of charges against Gai Waterhouse regarding treatment given to the mare and records kept by the stable were adjourned.

More Joyous is at Singleton's property until a decision is made whether she continues racing or goes to stud.

"There is a possibility she could be retired," Singleton's racing manager Duncan Grimley said.

"Frankel is still on the agenda."

Singleton has booked More Joyous for a date with the unbeaten English horse who retired last year as the highest rated horse in the world.

He had not decided whether it would be this year or next. If he decides it will be sooner rather than later, More Joyous will travel to England to be mated with Frankel in September when he will cover a select book of mare to southern hemisphere time.

Grimley said most of the other horses in training had been sent to other stables.

"Two horses have been gone to Bjorn Baker, a Zabeel filly to Clarry Conners, Anthony Cummings has a More Than Ready colt while Tony McEvoy will get Most Joyful, the sister to More Joyous.

"There are six or seven yearlings that have yet to be divvied up."

Waterhouse trained More Joyous to 21 wins, eight at Group One level, from 33 starts.