Editorial: The very concept of women's sport is at risk by letting competitors with mostly male attributes take part

​There was an extraordinary moment in tennis more than 50 years ago when the male tennis player Bobby Riggs said that even at age 55 he could beat any woman at the game, so inferior did he think the fairer sex to be at tennis.​

Billie Jean King, aged 29, accepted the challenge and beat Riggs in straight sets. His humiliating defeat was a huge boost for women's tennis. More recently tennis prize money has been equalised between men and women.

In spite of that showdown, no-one doubts that if tennis became unisex men would dominate the tournaments due to the fact that they are stronger. It is one thing to recognise the genius in both male and female sports stars, and to agree that the sexes deserve equal respect in their endeavours. It is another to pretend there is no innate difference between the two.

However, the whole matter of trans sports people and athletes who are DSD (differences of sexual development) has come to the fore in the case of Iman Khelif, the Algerian boxer who is surging ahead at the Olympics. Khelif is competing in the women's category, despite reportedly failing gender eligibility tests at the Women's World Championships last year.

Khelif this week punched opponent Angela Carini so hard that she had to stop the game after 46 seconds. If competitors such as Khelif were disqualified it might be a personal tragedy for them but the loss of women's sport entirely would be a far greater tragedy. That is the ultimate outcome of allowing people with largely male physical attributes to compete in women’s categories.

Only a few years ago, such a scenario would have been seen as an outrage. Now the organisers of the Olympics apparently cannot see the injustices that allowing Khelif and Taiwan's Lin Yu-ting (who also failed an world championship gender eligibility test) to compete is causing, and the threat that it poses to the very idea of women's categories in sport.