Both trainers spent around 11 hours in a closed show cause hearing conducted by Racing Victoria stewards, which concluded early on Tuesday morning.
Weir, a five-time Melbourne premier trainer and the victor of the 2015 Melbourne Cup with Prince Of Penzance, employs around 150 people in his stables.
Racing Victoria stewards said that "given the severity of the charges" against Weir, they were seeking to suspend him from training for four years.
Australian trainer Darren Weir faces a four-year suspension from the sport after deciding not to contest charges against him for the possession of equipment used to deliver electric shocks to horses, Racing Victoria (RV) said on Monday.
As it stands, with Weir's assistant Jarrod McLean - also a licensed trainer - set to fight his charge relating to possession of a jigger, McLean is able to continue on training in the interim, although the stewards declared he cannot receive horses that were in the possession of Weir.
Darren Weir was charged with having devices known as "jiggers", which can make horses run faster.
At a preliminary teleconference late on Friday afternoon, stewards ordered all horses trained by Weir to be scratched from weekend races.
"To that end, stewards have requested that the RAD Board expedite the hearing of Mr Weir's charges at which point they will be seeking a four-year disqualification".
Racing Victoria's executive general manager - integrity, Jamie Stier said: "This is a complex matter, and the stewards were determined to be thorough and give due consideration to the submissions made, their legal advice and the ongoing investigations".
McLean will contest the charges he faces, while stable employee Tyson Kermond will not face any action after charges of failing to assist the stewards were not pursued.
Regarding McLean, significant conditions were also imposed until the RAD Board has heard and determined the charges. Until last week, he had more than 600 horses on his books with that number dwindling as owners begin transferring them to other trainers amid uncertainty over their autumn programs.