"Swimming has been my passion since I was 10 years old and I would never intentionally take a banned substance that would disrespect my sport or jeopardise my career."
The swimmer had suggested that she took a tainted supplement and that is how Ligandrol came to be in her system.
Her lawyers would need to argue and prove that her supplement was tainted to prove Jack's innocence.
Former ASADA head Richard Ings told The Daily Telegraph the four-year ban is standard.
"I wouldn't draw any conclusion from the four-year ban, that happens in every matter. The issuing of notification of a four-year ban is standard practice in all these matters," Mr Ings said.
Jack's manager Philip Stoneman said the swimmer wouldn't contest the presence of the banned drug in her system.
"I don't think this is a question of Shayna denying there is something in her body," Stoneman said on Monday.
"What she is doing is fighting her innocence because it shouldn't be in there and she doesn't know how it got in there."
On a rough day for Jack she already copped a hefty financial blow when she was banned by the lucrative International Swimming League (ISL).
Jack had been included in the Cali Condors team for the ISL's series starting this October.
But the ISL says Jack has been suspended from the league, pending the outcome of her doping case.
The ISL's managing director Andrea di Nino says Jack's selection has been revoked for the meets to be held in Europe and the United States from October.
"No doping control rules violation will be overlooked," Mr di Nino said in a statement on the ISL's website.
"This is another case that serves to reiterate our stance on banned substances and breaking doping control rules. No such behaviour will ever be condoned.
"From the outset, the ISL has been an advocate for transparency and clean sport.
"Any athletes with doping control or ethical violation records will be considered ineligible with no recourse."
The ISL has been founded and funded by Ukrainian billionaire and swimming fan Konstantin Grigorishin, who has earmarked a $US20 million budget for the initial series, of which $7 million will go to swimmers and teams in prize money.
The incident with Jack had already caused massive amounts of embarrassment for Australian Swimming as news of Jack's positive test came just days after Dolphins teammate Mack Horton had made his podium protest against Chinese star and convicted doper Sun Yang.
However Swimming Australia CEO Leigh Russell had seemingly washed her hands of Jack and insisted that her organisation were not at fault for the embarrassment Horton may have suffered.
"I can appreciate that sentiment (that Horton was thrown under the bus), but what I would say is that Mack and us at Swimming Australia have that zero tolerance to drugs and (we have) that policy," Russell said on Monday.
"We've backed his stance, we backed it at the time and we certainly back it now. We will continue to have a zero tolerance approach to drugs in sport."