A ban on transgender women participating in the Olympics looks set to be announced, with all affected athletes barred from the upcoming games in 2028.

This major overhaul of rules surrounding the role of transgender women at the top end of sport follows reports of a lengthy scientific review of evidence regarding the potential biological advantages of being born male.

The expected significant change in International Olympic Committee (IOC) guidance for female competition is likely to take effect from next year, according to The Times.

No such rules have reportedly been implemented for trans men, however.

Although the rules around transgender participation have been a matter of highly fraught debate for well over a decade, competition guidelines for female athletes have largely been based on acceptable levels of testosterone, with each sport setting its own rules on participation.

The IOC’s newest president, Kirsty Coventry, has previously spoken of ‘overwhelming support’ towards protecting the female category of sport.

Kirsty Coventry stepped into the IOC role promising to protect women’s sports (STEFANO RELLANDINI/Getty Images)

In June, after her election to the role, Coventry said: “There was overwhelming support that we should protect the female category. And with that, we will set up a working group made up of experts and international federations.

“It was agreed by the members that the IOC should take a leading role in this. And that we should be the ones to bring together the experts and the international federations and ensure that we find consensus.

“We understand that there will be differences depending on the sports. But it was fully agreed that as members that, as the IOC, we should make the effort to place emphasis on protection of the female category.”

According to The Times, medical and scientific director Dr Jane Thornton had presented the early findings of a scientific review into the impact that differences in sexual development can have on fair competition.

Sources told the publication that Dr Thornton’s findings supposedly showed that people who are born male retain a physical advantage over cisgender women, even when testosterone levels are controlled for.

Guidelines for female athletes have previously mostly been based on levels of testosterone (Getty Stock Photo)

“It was a very scientific, factual and unemotional presentation which quite clearly laid out the evidence,” one source claimed.

An IOC spokesperson has since issued a statement on the matter, telling Sky News: “An update was given by the IOC medical and scientific director to the IOC members last week at the commission meetings.

“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 Times further reports that it is believed that the IOC will announce its new policy early in the new year, possibly around the Milan-Cortina winter Olympics in early February.

It is also reported to be covering differences of sex development (DSD), which are rare conditions which make a person’s reproductive, hormonal, or chromosomal sex atypical.