The International Olympic Committee says "no decisions have been taken yet" amid reports transgender athletes could be banned from the female category in all Olympic events.
It was reported on Monday that athletes born male were set to be barred, after a scientific review found male advantages remained even after athletes took steps to reduce testosterone levels.
The formation of a working group looking at the protection of the female category was one of the first acts of new IOC president Kirsty Coventry when she formally succeeded Thomas Bach in June.
The IOC confirmed on Monday that its medical and scientific director Dr Jane Thornton had updated IOC members last week on the initial findings of a scientific review, but a spokesperson said: "The working group is continuing its discussions on this topic and no decisions have been taken yet. Further information will be provided in due course."
The IOC has previously left other sports to set their own policies around transgender inclusion, with its 2021 framework stating there should be "no presumption of advantage" pertaining to trans athletes.
Coventry said in June she hoped the new working group could "find consensus" and give all Olympic sports clear guidance.
Athletics and boxing have already introduced mandatory sex testing for athletes wishing to enter their female categories.
Reports on Monday said the IOC's new policy could be announced early next year, possibly at the IOC Session in Milan ahead of the Winter Olympics.
In February, United States president Donald Trump signed an executive order banning transgender athletes from competing in female sports categories, a policy he intends to apply at the Los Angeles Olympics in 2028.
Reports said it was likely athletes born with differences of sexual development (DSD) would also be barred from the female category in Olympic sports.
There was controversy at the 2024 Paris Olympics when Imane Khelif and Lin Yu-Ting won gold medals in the women's boxing, a competition directly overseen by the IOC, despite having been disqualified from the previous year's World Championships for allegedly failing to meet gender eligibility criteria.
Khelif has always insisted she was born a woman, has lived as a woman and has competed as a woman. World Boxing, which now oversees the sport at international level, has introduced mandatory sex testing.
Reacting to the reports of an imminent IOC ban on transgender athletes, Fiona McAnena from campaign group Sex Matters said: "This is a triumph of common sense over transgender ideology.
"A few international sports federations such as World Athletics, World Aquatics and World Rugby thought for themselves, but far too many sports bodies pointed to the IOC and claimed that they were merely following best practice.
"Now that the IOC has found the backbone to do the right thing, every international sports body must fall into line and ban everyone male from the female category."
Shadow Equalities Minister Claire Coutinho said: "Today's reported common sense decision by IOC is welcome and marks a decisive moment for fairness in sport.
"It is scandalous that biological men were ever allowed to compete in female categories, and [Conservative leader] Kemi Badenoch has led calls for these common sense restrictions. For too long women missed out on medals and were put at risk of injury."
SportNews' Sports News Correspondent Geraint Hughes:
"The IOC has in some parts been able to sit on the sidelines and watch what governing bodies of individual sports are doing, for example athletics and boxing - two huge Olympic sports.
"In the UK, the Rugby Football Union [RFU] and Rugby Football League [RFL] have banned transgender athletes from competing in female competitions. There is momentum for sporting federations to determine a very clear policy, whereas perhaps a few years ago that was not the case.
"Look at the mess we had in Paris 2024 for the Olympics around Imane Khelif. Let's make this clear - she is not a transgender athlete nor do we know whether she has DSD (differences in sex development).
"It became quite toxic at times, the debate around her, so we need to avoid that which is another reason for this shift in momentum. As well as the fact that we're heading towards the next Olympic Games being in the USA.
"There is a lot of pressure coming from the Trump administration around stopping athletes who have transitioned from male to female being able to compete in the female category.
"So there is no ambiguity about where president Trump sits on this issue.
"No decisions will be made in the short-term but I think it's fair to say that you can see there's momentum towards discussion on the potential for a blanket ban by the IOC."
