Because of the cancellation, Mylan Pharmaceuticals - which manufactures the pill - will be allowed to tender to supply it to the Department of Health.

The cancelled agreement was between Mylan and Aspen Pharmacare, which supplies a three-pill ARV course to the government.

The agreement, according to the Treatment Action Campaign, prevented Mylan from distributing its three-in-one ARV pill in South Africa until 2016.

On Friday, government announced a new tender for ARV medication to be supplied next year.

Activists are hoping that, from next year, people receiving ARV medication from the government will have to take only one pill a day.

South Africa has the world's largest ARV programme, with most government patients taking first-line treatment, which consists of three different tablets a day.

According to Médecins Sans Frontièrs, the three-pill combination costs the government R113 a month per patient.

The current three-in-one pills cost four times more than the three separate ARVs being supplied to the government.

Health workers believe prescribing three-in-one pills improves patient compliance.

The Treatment Action Campaign said three-in-one pills "simplify treatment, cutting down the number of tablets that a person has to take daily. They also allow patients to take their medication more discreetly . they improve treatment adherence."

On Friday, Médecins Sans Frontièrs was told that the agreement that had stopped Mylan from distributing its cheap three-in-one antiretroviral pill had been cancelled.

Aspen senior executive Stavros Nicolaou said the agreement was no longer in place and that Mylan could now bring the three-in-one to South Africa.

Health activists, who have expressed relief, are now calling for all pharmaceutical companies to make three-in-ones available more cheaply.

Médecins Sans Frontièrs' Gilles van Cutsem said: "We hope the pricing for [the pills] will be in line with international pricing.

"It would be totally unacceptable if the government is not able to procure [three-in-onepills] at internationally competitive prices,l or even lower, given that South Africa has the highest HIV burden in the world and consumes 21% of the world's ARV supply."

He said he hoped that now that the agreement between Aspen and Mylan had been relaxed there would be no collusion on the pricing of three-in-ones.

"Mylan and Aspen are currently the only two companies to have registered a first-line regimen three-in-one pill in South Africa, with Aspen buying pharmaceutical ingredients from Mylan.

"We hope these companies do not abuse a quasi-monopolistic situation to offer the South African government artificially high prices for life-saving drugs."

Mylan refused to comment when contacted by The Times.