South Africa's border police stopped a truck from Malawi that was driving into the country with drugs worth nearly one billion rand ($61 million), authorities said on Thursday.

In an eight-hour search, security forces uncovered more than 700 kilograms (1,540 pounds) of methaqualone, which is used to make the highly addictive drug Mandrax, the border authority said.

The estimated street value of the haul was almost one billion rand, it said in a statement.

Two Malawi nationals and one Zambian were arrested, a spokeswoman told AFP.

Investigations underway

While South Africa has a strong market for mandrax, the statement said investigations were underway to determine "the intended destination of the substance and whether the syndicate forms part of a broader transnational criminal network operating within the region or globally".

In the past two years, there have been at least four major busts of drug-manufacturing labs in South Africa involving Mexican nationals, raising suspicions that Mexican cartels are trying to establish themselves in the region.

The Geneva-based Global Initiative Against Transnational Organized Crime said in a July 2025 report that there had been a proliferation of "Mexican meth" labs around the globe over the past decade.

In July 2024, South Africa’s elite Hawks unit arrested three Mexicans in a raid on a drugs lab on a farm near Groblersdal, about 200 kilometres from Johannesburg, when they seized about two billion rands worth of methamphetamine.