Caster Semenya will be able to compete during her appeal to the Federal Supreme Court of Switzerland after the International Association of Athletics Federations (IAAF) saw a request to reimpose regulations denied.
Last week, the court ordered the rules which force athletes with differences in sexual development (DSD) to take drugs to medically reduce their naturally-occurring testosterone if they want to compete at events ranging from 400 metres to a mile be put on hold with immediate effect.
The court said its "superprovisional order", considered a major boost for South Africa's Semenya in her challenge against a Court of Arbitration for Sport (CAS) decision which ruled in the IAAF's favour, would be in place until June 25.
In response, the IAAF said it would "seek a swift reversion of the superprovisional order moving forwards so that the DSD Regulations apply to all affected athletes in order (among other things) to avoid serious confusion among athletes and event organisers and to protect the integrity of the sport".
The worldwide governing body also confirmed the court's ruling only applied to the double Olympic and three-times 800m world champion.
"After considering the IAAF's arguments, the Court has now determined in a second order that the IAAF's request failed to set out any reason or change in circumstance that would justify a reconsideration of the prior order,” a statement from Semenya’s lawyers said.
"This means that Caster remains permitted to compete without restriction in the female category at this time."
Three-times world champion Semenya added: "No woman should be subjected to these rules.
“I thought hard about not running the 800m in solidarity unless all women can run free.
“But I will run now to show the IAAF that they cannot drug us."
Semenya’s legal team had claimed the South African has been prevented from competing in the 800m at the upcoming Diamond League event in Rabat.
Her lawyers claim they are seeking clarity over the reasons for the decision.
The competition in the Moroccan city is due to take place on Sunday (June 16).
Invitations to the events are handled by the meet organiser, rather than the IAAF.
The local organising committee have since confirmed Semenya has been invited to compete in the 800m.
insidethegames understands no response has yet been given to the invitation, leaving it unclear as to whether Semenya will compete in two days time.
On Monday (June 10), Semenya was named in South Africa's preliminary squad for the 2019 IAAF World Championships to compete at 800m, but her inclusion depends on the outcome of her appeal.
The IAAF’s rules, which came into force on May 8, mean DSD athletes with naturally high levels of testosterone who wish to participate in events between 400m and a mile must medically limit that level to under 5 nmol/L, double the normal female range of below 2 nmol/L.
They were described as "discriminatory" by the CAS when it ruled in favour of the IAAF and against Semenya but it also said the policy was "necessary, reasonable and proportionate" to protect the fairness of women's sport.