The Medicines Control Council (MCC) and the Department of Health want to stop a company from marketing and selling medicines containing the ingredient dextropropoxyphene.
DPP containing medicines have been withdrawn in Europe, the US and Singapore.
Adcock Ingram produces Synap Forte which contains DPP.
The MCC said drugs like Synap Forte pose a health risk to patients.
In April it decided to withdraw the registration of DPP containing medicines, but an appeal by Adcock Ingram and a subsequent out-of-court settlement meant that the decision could not be implemented.
Attorney Nicki Steyn explained why the court order should be rescinded.
"The representatives who entered into a settlement agreement on behalf of the applicants were not authorised to do so," she added.
This is a complicated case compounded by the fact that the appeal was still pending.
Meanwhile, lawyers will argue that the public interest was great and urgent intervention was needed.