John Allen has been quizzed about his tactics in the Grand National Hurdle at Sandown with stewards adjourning the inquiry to examine betting on the race.
Allen rode the Darren Weir-trained Bit Of A Lad ($4.60) into third place behind Cougar Express in the 4200m-race on Sunday with the horse coming off victories at Casterton, Warrnambool and Bendigo.
Bit Of A Lad was sent out second favourite behind runner-up Self Sense who was the $2.05 top pick.
Rob Montgomery, who presided at Sunday's meeting, said Racing Victoria stewards wanted to examine betting records from corporate bookmakers before continuing the inquiry.
He said stewards had spoken with Weir who is in Darwin for the Cup meeting.
"He (Weir) said he didn't tie down Mr Allen with instructions other than not to let Self Sense out of his sight," Montgomery said.
"The only way to beat him was to pressure him."
Allen said he had ridden Bit Of A Lad in a bid to give the gelding every chance of toppling the favourite.
He added the way he thought the race would unfold was that he would sit outside the leader, whether that was Self Sense or Cougar Express.
"I thought I gave him every chance and I rode my horse the same way as last time," Allen told the inquiry.
Jackson was fined $500 for standing in the saddle in a celebratory gesture before the finishing line.
Last season's premier jockey Craig Williams was suspended for 10 meetings on a careless riding charge after winning on Smart Elissim.
His suspension begins immediately and he can return on August 16.