Two Namibian sprinters have been blocked from competing in the women’s 400m at the Olympics because their natural testosterone levels have been deemed too high.

Christine Mboma and Beatrice Masilingi, who are both cisgender women, were forced to undergo medical assessments while they were at a training camp in Italy.

The tests were requested by World Athletics, according to the Namibia Olympic Committee, and their results “indicated that both athletes have a natural high testosterone level,” a statement continued.

“According to the rules of World Athletics, this means that they are not eligible to participate in events from 400m to 1600m,” officials added.

“Both Christine and Beatrice will be able to compete in the 100m and 200m events,” the statement added.

NBC reported Mbomba ran 48.54 seconds to win a 400m race in Poland on Wednesday (30 June), which was an under-20 world record and the seventh-fastest 400m by a woman of all time, suggesting she may well have taken the gold medal.

Masilingi had the third-fastest time behind Mbomba and Shaunae Miller-Uibo of the Bahamas, the current Olympic champion.

Namibian sprinters hit by same rule that tried to force Caster Semenya to alter her body

World Athletics has previously been criticised over its rules for athletes with so-called “differences of sexual development” (DSD).

It introduced the current limits on testosterone levels for female athletes in 2018 before they came into effect a year later.

The rules apply for races between 400m and one mile and combined events over the same distances, and forces certain women to artificially alter their natural hormone levels should they wish to compete. The UN has condemned such practices as “unnecessary, humiliating and harmful”.

Most famously, the rule curtailed the career of Caster Semenya, a cisgender woman who is a two-time Olympic champion.

Semenya has launched several legal appeals against the ban, calling the rules unfair and discriminatory. The Court of Arbitration for Sport rejected her challenge in May 2019. She appealed the decision to the Federal Supreme Court of Switzerland, which ultimately rejected her case in September 2020.

Semenya filed an appeal with the European Court of Human Rights in February this year. There has been no ruling yet.

In April, she admitted to the Guardian that the long legal battle has taken “the soul out of my body”. She added that she refused to undergo treatment to lower her natural testosterone level.

“They want me to take my own system down,” Semenya told the Guardian. “I’m not sick. I don’t need drugs. I will never do that.”