A leading United Nations adviser will on Tuesday call for the return of mandatory sex testing to ensure that the female category in sport is accessible exclusively to those born female.

Reem Alsalem, the UN special rapporteur on violence against women and girls, argues that the tests, which could involve a cheek swab, are essential to prevent a repeat of this year’s scandal at the Paris Olympics, where two biologically male boxers were allowed to fight women.

The extraordinary report lays bare the scale of the problem, with Alsalem illustrating how governing bodies’ failure to act on the problem has led to more than 600 female athletes around the world losing over 890 medals in 29 different sports.

While the International Olympic Committee insists it will not return to the “bad old days” of sex testing, Alsalem argues: “There are circumstances in which sex screenings are necessary, legitimate and proportional to ensure fairness and safety in sports. At the Olympics, female boxers had to compete against two boxers whose sex as females was seriously contested, but the IOC refused to carry out screening. Current technology enables a reliable sex screening procedure through a simple cheek swab for non-invasiveness, confidentiality and dignity.”

Between 1968 and 1999, the IOC officially required sex verification for female athletes, with the rationale to prevent those masquerading as women and those with “unfair, male-like advantage” from competing in female-only events. The policy had broad approval: 82 per cent of the 928 female Olympians surveyed at the 1996 Atlanta Games expressed support.

The IOC’s decision to abandon it has created enormous controversy, and never more so than when Algeria’s Imane Khelif and Lin Yu-ting of Taiwan – two boxers whose testing outside the Olympics had revealed the presence of XY chromosomes, the male pattern – were permitted into women’s bouts in Paris. Both went on to win gold medals.

So intense was the backlash that some of the boxers’ beaten opponents began crossing their hands twice in the air in an ‘XX’ gesture, as a statement to the IOC that their sport needed to be kept female-only. It is a view that Alsalem endorses in her report, delivered on Tuesday to the UN General Assembly in New York.