Victoria's peak horseracing body is investigating the possibility that Damien Oliver isn't the only big punter in the state's riding ranks.

Racing Victoria (RV) chief executive Rob Hines said various investigations were under way, instigated by a team that monitors betting patterns on most of the 4000 races run in Victoria every year.

"There are a number of ongoing investigations," Hines said.

"Some of those may lead to inquiries and charges."

RV stewards laid long-anticipated charges against Oliver on Tuesday, some three weeks after it emerged he was under investigation for placing a $10,000 bet on a rival horse and rider at a Moonee Valley meeting in October 2010.

The charges followed a written admission to a charge of betting on the horse Miss Octopussy, the favourite and winner of a race in which Oliver rode the second favourite, and to another charge of using a mobile phone while in the jockeys' room to place the bet through a third party.

The admission was tendered by Oliver to RV on Monday.

The Oliver case ranks among the most scandalous in the sport in decades, not because of the sinister nature of the charge, but because it involves one of the world's greatest jockeys.

Oliver is one of the highest-profile jockeys in Australia, mostly for the right reasons.

The 40-year-old has won seven Melbourne jockeys' premierships, two Melbourne Cups, four Caulfield Cups, two Cox Plates and a Golden Slipper.

He has won races in almost every major racing nation, including England, Hong Kong and Japan, and has handled some of the champions of the Australian turf.

Oliver, whose father died in a race fall in Western Australia when he was three years old, also rose to prominence in the lead-up to the 2002 Melbourne Cup when his older brother Jason died in a fall on the training track in Perth in the week before the big race.

The day before burying Jason, he rode Media Puzzle to victory in the Cup, his kiss to the heavens as he crossed the line now a part of racing folklore.

Oliver's betting breach generated a string of mostly unfounded revelations, including one that he had made official admissions relating to the current charges a week ago.

The reports prompted criticism of RV for not standing him down pending the result of a hearing and suggestions the organisation wasn't doing enough to safeguard the integrity of one of the state's biggest industries.

RV dismissed such claims on Tuesday, saying its stewards were "on the front foot" throughout the investigation and it had been legally impossible to act before Monday's admissions came to light.

"It has been alleged in various news reports that Damien Oliver had confessed to the illegal bet on Miss Octopussy some weeks ago," Hines said.

"Following a number of interviews ... a signed statement was received yesterday from Mr Oliver which contained an admission which enabled the stewards to lay the charges and stand down Mr Oliver pending the inquiry."

The charges against Oliver will be heard on Tuesday.