Racing Victoria has released a pair of statements, with chief executive Giles Thompson addressing the charges and announcing an inquiry.
"The core responsibility of Racing Victoria is to protect the integrity of the sport and to enforce the Australian Rules of Racing, ensuring both a level playing field for all and the health and welfare of horses competing in Victorian races. This is a responsibility that we take very seriously," Mr Thompson said in the statement.
"In the course of discharging their duties, our Integrity Services team commenced an investigation into the activities of licensed persons in the Warrnambool and Ballarat areas.
"During the course of our investigation, the Integrity Services team sought the support of Victoria Police's Sporting Integrity Intelligence Unit on the matter thus instigating their investigation.
"Victoria Police have today issued charges against four persons as a result of their investigation which included the execution of warrants at properties in the Warrnambool and Ballarat areas on 30 January 2019.
"These are serious charges and the nature of the alleged conduct described within the charges is distressing to all within the racing industry, as well as the general community.
"Upon the issuing of charges today, our stewards have immediately opened inquiries and ordered three persons to attend tomorrow afternoon to answer questions in relation to the charges. Those inquiries will dictate our next steps."
"Racing Victoria (RV) Stewards will open inquiries from 2pm tomorrow, Thursday, 10 October 2019, in relation to the charges issued today against four persons by Victoria Police's Sporting Integrity Intelligence Unit (the Unit). The inquiries will be held at the offices of RV," the second statement reads.
"The charges emanate from the Unit's investigation into the activities of licensed or registered persons in the Warrnambool and Ballarat areas, including the execution of warrants at properties on 30 January 2019.
"Stewards have directed a licensed trainer and two registered stable employees to attend inquiries and answer questions in relation to the charges.
"Licensed trainer Jarrod McLean has been directed to attend at 2pm, registered stable employee Tyson Kermond at 3pm and, licensed rider agent and registered stable employee William Hernan at 4pm.
"Former licensed trainer, Darren Weir, who has also been named in the media today in connection with the charges is currently a disqualified person serving a four-year ban over charges laid earlier this year by RV Stewards under the Rules of Racing.
"Mr Weir will be directed to attend an inquiry on a date to be fixed."
Disqualified trainer Darren Weir has been charged by police with defrauding racing officials and animal cruelty, after jiggers were seized during January property raids.
Detectives from the Sporting Integrity Intelligence Unit charged four men on Wednesday.
The 49-year-old Weir, who now lives in Baringhup near Maldon, has been charged with nine offences.
Charges against the former trainer include conspiracy to defraud Racing Victoria stewards, three counts of engaging in torturing, abusing, overworking a thoroughbred race horse, three counts of causing unreasonable pain or suffering to a race horse, possessing an unregistered fire arm and using a controlled weapon without excuse.
A 38-year-old Yangery man has been charged with 16 offences, including conspiracy, two counts of engaging in conduct that corrupts or would corrupt a betting outcome and animal cruelty.
A 27-year-old Warrnambool man has been charged with seven offences, including cruelty to animals and conspiracy to defraud racing stewards. A 31-year-old Warrnambool man has been charged with one count of using corrupt conduct information.
A police media spokeswoman said the charges were "part of an investigation into alleged illegal activity within the thoroughbred racing industry".
The charges have emerged from warrants executed at properties in Miners Rest and Warrnambool on January 30 this year.
A number of items, according to the media spokeswoman, including a firearm and what is believed to be conducted energy devices (jiggers) were seized from the properties.
All four men will appear at Melbourne Magistrates Court on 23 October.
In a short statement, Racing Victoria confirmed it had been advised of the police charges.
"RV Stewards are giving these matters careful consideration and will provide a further update in due course," it said.
Weir's properties were sensationally raided by police in January and the findings led to the champion trainer being disqualified from racing for four years.
He was found guilty on charges of possessing electronic equipment ("jiggers") that could be used on horses and of conduct prejudicial to the image of racing.
It was a shattering blow for Weir and for the community in Miners Rest, where he had employed a large number of people.
READ MORE: HOW WEIR ROSE TO THE TOP
After the ban was handed down, Weir's stables in Miners Rest were purchased by the training partnership of Ciaron Maher and David Eustace, which continue to race out of the premises.
Weir famously won the 2015 Melbourne Cup with Prince of Penzance, which was ridden by Michelle Payne. The triumph is part of a feature movie titled Ride Like A Girl.
He is a multiple Victorian metropolitan premiership winner, has claimed 36 group 1 races and holds the Australian record for most amount of winners in a single season.
Anyone with information about illegal activity is urged to contact Crime Stoppers on 1800 333 000 or submit a confidential crime report to www.crimestoppersvic.com.au
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