MELBOURNE, Australia (AFP) — Prominent horse trainer Robert Smerdon was banned for life Thursday along with two stablehands over a major Australian doping scandal involving more than 100 races over several years.

Two other trainers, Stuart Webb and Tony Vasil, were handed suspensions for three and four years, respectively, while three others got lighter punishments.

Smerdon and stablehand Greg Nelligan were found by a Racing Victoria investigation to be the masterminds of the scam, with all those involved linked to the Aquanita Racing stable.

In one of Australia’s biggest horse racing controversies, the eight were convicted by the Racing Appeals and Disciplinary Board of an unprecedented 271 breaches of race day rules between 2010-17.

Most of the offences related to dosing horses with a banned mixture of sodium bicarbonate, or baking soda, which helps reduce the build-up of lactic acid and improves performance.

Judge John Bowman said at a hearing in Melbourne’s County Court on Tuesday that it was “probably the biggest scandal and the most widespread investigation in the history of Australian racing”.

“This was a long-running, systematic conspiracy to try and obtain an unfair advantage in well over a hundred races over seven years,” he said.

It followed a four-month investigation by Racing Victoria stewards.

“It is imperative that we send the strongest possible message to the small minority who think they can undermine the integrity of our sport,” said Racing Victoria Chief Executive Giles Thompson after the sentencing.

“If people choose to try and brazenly cheat the system to gain an unfair advantage over all of the hard-working and committed participants who abide by the rules of racing, then we don’t want them to have a place in our sport.”

The disciplinary board is yet to consider whether the horses found to have received illegal sodium bicarbonate top-ups should be demoted from races they competed in.

Melbourne’s Herald Sun newspaper said there was also the prospect of owners whose runners were beaten by Aquanita horses seeking compensation.