Jockey Andrew Heffernan was among those to attend the first day of what could be a lengthy British Horseracing Authority disciplinary panel hearing corruption charges.
Heffernan, who had been riding in Australia, was stood down by Racing NSW in October when the charges were announced.
Eight unlicensed individuals also face corruption charges, headed by three footballers - Ipswich Town's Michael Chopra, former Manchester United player Mark Wilson and Doncaster Rovers winger James Coppinger.
Heffernan has been charged with communicating for reward information to betting exchange account holders over the prospects of horses he was riding in races, and unlicensced individuals acted on that information.
He is also charged with failing to ensure a horse ridden by him ran on its merits.
Chopra released a statement earlier this month revealing that he could not afford to defend himself at the hearing and would welcome a ban so he could overcome a gambling addiction problem.
He, along with Garner, Joshee, Shelley and Wilson have also been charged with offering bribes to Heffernan.
The jockey moved to Australia in late 2011. He rode in Western Australia until he was suspended for a jockeys' room altercation with an apprentice in May last year.
He then moved east to take up a position with the Paul Perry stable at Newcastle.
Ten working days have been set aside for the hearing, followed by a period of consideration by the panel.