The Court of Arbitration for Sport says a week-long hearing for South African athlete Caster Semenya's appeal against hormone regulations proposed by the international track and field body ended Friday. A decision in the "pivotal" case is expected in late March.

The Swiss-based court says the hearing ended with Semenya, the two-time Olympic 800-metre&nbsp;champion, having the "last word."

Caster Semenya appeal case mixes science, sports, gender politics

Caster Semenya's running future will be decided by three judges starting next week in a landmark case that will challenge science and gender politics. The two-time Olympic 800-meter champion from South Africa is looking to overturn eligibility rules for hyperandrogenic athletes.

South African runner Caster Semenya is looking to overturn eligibility rules for hyperandrogenic athletes in her appeal case starting Monday.

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What's the real problem with Caster Semenya?

Track and field's world governing body says its new testosterone-restricting rules are designed to ensure a level playing field. But are there darker factors at play in the battle against Caster Semenya and athletes like her?

South African athlete Caster Semenya (R) reacts after winning the women's 1500 metres during the Diamond League athletics competition at the Suhaim bin Hamad Stadium in Doha, on May 4, 2018. (Photo by KARIM JAAFAR / AFP) (Photo credit should read KARIM JAAFAR/AFP/Getty Images)

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With the IAAF's new testosterone-restricting rules not yet in effect, Caster Semenya has continued leaving opponents in her wake — to the chagrin of her critics.

Is track and field picking on Caster Semenya?

Track and field's governing body has introduced controversial new rules aimed at restricting testosterone levels in athletes competing in certain women's events. Some feel the move is aimed squarely, and unfairly, at the Olympic 800-metre champion.

GOLD COAST, AUSTRALIA - APRIL 13: Caster Semenya of South Africa celebrates wins gold in the Women's 800 metres final during athletics on day nine of the Gold Coast 2018 Commonwealth Games at Carrara Stadium on April 13, 2018 on the Gold Coast, Australia. (Photo by Michael Dodge/Getty Images)

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Reigning Olympic 800-metre champion Caster Semenya appears to be a target of efforts by track's governing body to limit testosterone levels in athletes competing in certain women's events.

IAAF president Sebastian Coe also spoke at the hearing, which has repercussions for the future of sport and how athletes with differences in sexual development are treated.

The IAAF wants Semenya and other female athletes with what it calls abnormally high natural levels of testosterone to lower those levels through medication to be eligible to compete in top events like the world championships and the Olympics in distances from 400 metres to the mile.

WATCH | Caster Semenya: Physical gift or unfair advantage?

Physical gift or unfair advantage? Caster Semenya takes IAAF to court

In a watershed moment for gender politics in sport, hyperandrogenic runner Caster Semenya is going to court against the International Association of Athletics Federations (IAAF) to fight their female eligibility rules. CBC Sports' Jacqueline Doorey explains.

The regulations were due to be implemented in November last year but were suspended pending Semenya's appeal to sport's highest court.

CAS says the hearing "was conducted in a cordial and respectful atmosphere" despite the emotive issue and the decade-long battle between Semenya and the IAAF.

Semenya's lawyers said at the outset of the hearing that the proposed regulations would discriminate against the runner for what was a "genetic gift."

CAS says the decision will be announced "on or before March 26."

Caster Semenya's appeal of hormone regulations at the Court of Arbitration for Sport concluded Friday in Lausanne, Switzerland, with a decision expected to arrive in late March.

Caster Semenya appeal case ends, decision expected in late March

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