One of Britain's highest-profile media figures has taken aim at Kiwi transgender athlete Laurel Hubbard's potential participation at the Tokyo Olympics.
Hubbard kept her hopes of competing at Tokyo alive last month when she won the women's super-heavyweight weightlifting contest at the Roma World Cup, the first Olympic qualifying event of the year.
Controversial media personality Piers Morgan, who has over seven million followers on Twitter, took issue with Hubbard's potential participation in Japan.
"This is insane. Women's rights to basic fairness & equality are getting destroyed at the altar of political correctness," Morgan posted on Twitter.
"Trans women born with biological male bodies have a massive physical advantage against women born with female bodies in any sport where power & strength are significant factors. This shouldn't be a contentious claim, it's just a rather obvious fact.
Hubbard finds herself at the centre of a fierce row over whether trans women have an unfair advantage in sport – an question the International Olympic Committee (IOC) and other sports bodies are still grappling with.
The inclusion of trans athletes in elite women's sport has become the subject of huge controversy, with critics arguing that being born male provides a physical advantage even after transition.
Officially, male-to-female trans athletes have been allowed to compete in the Olympics since 2016 if their testosterone levels remain low enough for a year, under IOC guidelines.
Asked about the policy, the IOC told the Thomson Reuters Foundation it was up to international sports federations to decide eligibility rules for specific sports and events.
Transgender athletes are not required to gain legal recognition of their gender identity nor undergo anatomical surgery to be eligible to compete.
But many leading sportswomen have condemned their inclusion, arguing that they have greater muscle mass, bone strength and lung capacity.
Three-time Australian Olympian Tamsyn Lewis has also questioned the fairness of transgender athletes being allowed to compete in women's sport.
The 41-year-old said there are too many unknowns regarding transgender and transitioning athletes to create a level playing field in women's competition.
The three-time Commonwealth Games gold medallist told 2GB radio it was a politically charged and sensitive topic that many did not want to address.
"There's been a lot of people who are scared to come out and say anything because of political correctness," she said.
The Tokyo 2020 Olympic games will see a number of transgender competitors, with the IOC rules forcing female competitors to remain below testosterone guidelines to compete as women.
Lewis believes the guidelines don't factor in the physical advantage of growing up and going through puberty as a male.
"If you've grown up a male and had testosterone your bone structure is different to the female, your upper body strength is going to remain, you've got greater lung capacity a larger heart size, there's too many unknowns about how much going through puberty and being born a male is going to effect your result," she said.
2GB host Ben Fordham argued Hubbard had an obvious physical advantage compared to the rest of her field, prompting Lewis to question whether the female category would remain fair with increasing transgender participants.
"If we don't take a stand, what's going to happen to the female category of sport?,' she said.
"You don't want to get to the point where we haven't tackled this issue head on and in a respectful manner, that in 20 years time we're seeing our kids grow up and compete in sports that they just actually can't win."