Prominent horse trainer Robert Smerdon has been banned for life along with two of his stable employees for their parts in the systematic doping of more than 100 races over a seven-year period in one of the biggest scandals in the Australian thoroughbred industry.

Judge John Bowman on Thursday said there was hierarchal ladder in the scheme in which five others were found guilty and that Smerdon was at the top of it.

Victoria state's Racing Appeals and Disciplinary Board (RAD) found the eight were guilty of dishonest, corrupt, fraudulent, improper or dishonorable practice for their involvement in giving horses a banned mixture of sodium bicarbonate, or baking soda, before big races. That was supposed to help reduce the build-up of lactic acid and allow the horses to run longer.

Stable hand and horse trailer driver Greg Nelligan and his wife, Denise, who was also employed by Smerdon's stable, were also given life bans.

Trainers Stuart Webb, Tony Vasil, Trent Pennuto and Liam Birchley, and stable hand Daniel Garland received bans of between one and four years.

The eight were found guilty of 271 charges, the bulk of which were levelled at Smerdon and Greg Nelligan.

Racing Victoria described the scheme as the darkest chapter in Australian racing and asked RAD to also fine Smerdon 100,000 Australian dollars ($75,000).

The board reserved its decision on the fine for 10 days to take financial submissions.

Appearing earlier at the hearing, Racing Victoria lawyer Jeff Gleeson said the group engaged in "systematic cheating" from 2010 to 2017.

"It has cast a shadow over thoroughbred racing," Gleeson said.

Racing Victoria chief executive Giles Thompson said the sport's governing bodies needed to uphold the highest levels of integrity.

"It is imperative that we send the strongest possible message to the small minority who think they can undermine the integrity of our sport," Thompson said. "If people choose to try and brazenly cheat the system to gain an unfair advantage . then we don't want them to have a place in our sport."

All eight have the right to appeal their bans within 28 days.