Hubbard's case created intense social media comment yesterday. A number of posters expressed sympathy for Lambrechs and claimed Hubbard was advantaged over her female rivals because she had a strong competitive background in weightlifting as a man and will have retained a superior strength base.
But others reflected a more empathetic line, many urging sports and its fans to fall into line with changing social attitudes to an issue that sport has traditionally struggled with and wishing Hubbard well.
The issue of gender verification first gained global attention after South African runner Caster Semenya was ordered to undergo sex tests after winning the 800m world title in 2009. She was eventually cleared to compete by the IAAF and won silver in the 800m at the 2012 London Olympics.
The IOC used to conduct gender verification tests at the Olympics, but those chromosome-based screenings were dropped before the 2000 Sydney Games because they were deemed unscientific and unethical.
In the middle of last year, the International Olympic Committee decided transgender athletes should be allowed to compete in the Olympics and other international events such as the Commonwealth Games without undergoing sex reassignment surgery.
The IOC said new guidelines were needed to adapt to current scientific, social and legal attitudes on transgender issues.
"I don't think many federations have rules on defining eligibility of transgender individuals," IOC medical director Dr Richard Budgett said at the time. "This should give them the confidence and stimulus to put these rules in place."
The International Weightlifting Federation adopted the guidelines and they were followed by OWNZ in selecting Hubbard for the Australian event this month.
Under the previous IOC guidelines, approved in 2003, athletes who transitioned from male to female or vice versa were required to have reassignment surgery followed by at least two years of hormone therapy in order to be eligible to compete.
Now, surgery is no longer be required, with female-to-male transgender athletes eligible to take part in men's competitions "without restriction".
Meanwhile, male-to-female transgender athletes need to demonstrate that their testosterone level has been below a certain cut-off point for at least one year before their first competition.
"It is necessary to ensure insofar as possible that trans athletes are not excluded from the opportunity to participate in sporting competition," the IOC said. "The over-riding sporting objective is and remains the guarantee of fair competition. To require surgical anatomical changes as a precondition to participation is not necessary to preserve fair competition and may be inconsistent with developing legislation and notions of human rights."
Former IOC medical commission chairman Arne Ljungqvist, who was among the experts involved in drafting the new guidelines, said the consensus was driven by social and political changes.
"It has become much more of a social issue than in the past," he told Associated Press. "We had to review and look into this from a new angle. We needed to adapt to the modern legislation around the world. We felt we cannot impose a surgery if that is no longer a legal requirement.
"Those cases are very few, but we had to answer the question. It is an adaptation to a human rights issue. This is an important matter. It's a trend of being more flexible and more liberal."
Under the new rules, an athlete transitioning to a woman must undergo hormone therapy and demonstrate that the total level of male testosterone in the blood has been below 10 nanomols per litre for at least a year before competing. Hubbard has satisfied this requirement, say weightlifting officials.
The previous rule stated that, in addition to reassignment surgery, the athlete required a minimum of two years of hormone treatment. How long it will take the athlete to reach the new cutoff limit will depend on individual cases, Ljungqvist said.
"If you change sex, you will have to have a hormone level below 10 for 12 months," he said. "You don't go below 10 from day one. It takes quite some time. It can take more than one year or two years."
