Born in 1999, Imane Khelif of Algeria won her opening Olympic boxing bout Thursday when opponent Angela Carini of Italy quit after just 46 seconds, reigniting the debate about who is eligible to compete in women's sports.

After Khelif’s hand was raised to signal her victory, Carini dropped to her knees in tears, according to international media.

The manner of Carini’s defeat prompted concern and anger both in the boxing world and beyond. 

Khelif was disqualified from the 2023 world championships after failing an unspecified gender eligibility test, and her presence at the Paris Olympics has become a divisive issue, reported CNN.

Trump, Meloni, author JK Rowling, and billionaire Elon Musk have complained about Khelif being allowed to compete.

The fight has become a flashpoint for an often misinformed debate about how women are allowed to compete in sports, and also triggered an onslaught of online abuse.

Transphobic commentators incorrectly called Khelif ‘a man’ because of an alleged physical advantage.

The International Olympic Committee (IOC), however, strongly supports her participation in the 2024 Games, with IOC spokesperson Mark Adams saying she was “born female, was registered female, lived her life as a female, boxed as a female, and has a female passport.”

“This is not a transgender case,” Adams added.

Many athletes have written in support of Khelif, including Irish boxer Amy Broadhurst – who fought and beat Khelif in the World Championships. Broadhurst posted a picture of the pair before their 2022 match on X, saying: “Please, the hate has been ridiculous.”

Facing the same fate, Lin Yu‑ting of Taiwan won her opening Olympic boxing bout on Friday, beating Sitora Turdibekova of Uzbekistan 5:0 in the women’s 57-kilogram division, becoming the second boxer embroiled in gender controversy at the Olympics.

The controversy surrounding Lin originated from the disqualification of the two boxers from the 2023 IBA Women's World Boxing Championships.

Khelif and Lin have suddenly received massive scrutiny for their presence in Paris after years of amateur competition. 

Lin won International Boxing Association (IBA) world championships in 2018 and 2022, but the governing body stripped her of a bronze medal last year because it claimed she failed to meet unspecified eligibility requirements in a biochemical test.

Meanwhile, Khelif won a silver medal at the IBA’s 2022 world championships. However, the IBA,  which has been banned from the Olympics since 2019 after years of disputes with the IOC, disqualified her from last year’s championships shortly before her gold-medal match because of what it claimed were elevated levels of testosterone.

In June 2023, the IOC stripped the IBA of its status as the global governing body for boxing because of failures to complete reforms on governance, finance, and ethical issues.

The IOC is therefore running the boxing competition at the Paris Games and allowed Khelif and Lin to compete under its own eligibility guidelines.

The IOC has defended its decision to allow the two boxers who failed a gender eligibility test to compete at Paris 2024, The Independent reported.

The Paris 2024 Boxing Unit and IOC released a statement on Thursday about the ongoing controversy and asserted that like previous competitions, “the gender and age of the athletes are based on their passport,” according to American conservative editorial magazine National Review.

Lin has been an elite-level amateur boxer for a decade and Khelif for six years. 

“Everyone competing in the women’s category is complying with the competition eligibility rules,” IOC spokesperson Mark Adams said. 

“They are women in their passports and it’s stated that this is the case, that they are female.”

IOC president Thomas Bach said Saturday the ‘hate speech’ directed at Algerian boxer Khelif  and Lin at the Paris Olympics is "totally unacceptable."

"We have two boxers who are born as women, who have been raised as women, who have a passport as a woman and have competed for many years as women," Bach said. 

Sex testing in sports has come under scrutiny from groups like Human Rights Watch, who say that they violate fundamental rights to privacy and dignity.

The tests that the IBA claimed disqualified Khelif and Lin from competing in 2023 are confidential – so there is no way of knowing why exactly they were barred last year.

Female athletes that have differences of sexual development (DSD) are often subject to such tests.

DSD is a group of conditions involving genes, hormones, and reproductive organs and can be associated with a condition where a female body naturally produces more testosterone than others. 

The controversy surrounding Khelif and Lin is the first around DSD athletes in combat sports at the Olympics. 

There have been examples of transgender athletes competing in lower levels, such as Fallon Fox in mixed martial arts and Mack Beggs in high school girls wrestling, but neither of those examples are good comparisons because neither Khelif nor Lin is known to be transgender.

Khelif competed in the quarterfinals on Saturday, and Lin's quarterfinal is scheduled for Sunday against Bulgaria's Svetlana Kamenova Staneva. 

The IOC has vigorously defended its decision to include both athletes and it is not expected that either athlete will be ruled ineligible during this competition.