Police in Johannesburg say they have recovered nearly 30 tonnes of stolen platinum dust.

The dust was found in two 'horse-and-trailer' trucks during an investigation of a hijack on a security vehicle, a spokesperson revealed.

Inspector Amanda Roestoff told News24 that it was not yet apparent how the dust came to be in the vehicles, but that it was investigating further.

The dust was found in vehicles belonging to Freight Dynamics at premises in Aeroton in the south of the city.

On Sunday two Protea Security guards were kidnapped and their vehicle hijacked, when four men posing as policemen forced them off the road.

The West Rand anti-hijacking unit began exploring the case, recovering the vehicle in Devland last night.

From this discovery the police found links to the Scania premises, where the dust was located.