The two were arrested on Saturday following a tip off that there was a car transporting rhino horns.

It is one of the biggest hauls of rhino horns in the country, according to an elite police unit that investigates specialised types of crime known as the Hawks.

"We arrested them on Saturday in the Hartbeespoort dam area. They were driving in a vehicle and they were intercepted," Hawks spokesman brigadier Hangwani Mulaudzi told AFP.

"It was an intelligence-driven operation that led to the arrest of the two. They were found in possession of those 167 rhino horns," he said, adding "it is one of biggest (hauls)".

The suspects aged 57 and 61 years are expected to appear in the Brits town magistrate court on Monday.

Police said the rhino horns worth a "substantial amount of money" were destined for the Southeast Asian markets.

Demand for rhino horn is primarily fuelled by consumers in China and Vietnam where it is advertised by some traditional medicine practitioners as a wonder ingredient.

In reality rhino horn is a nostrum, comprised of little more than keratin, the same protein that makes human hair and fingernails.

Nonetheless horn can fetch up to $60,000 per kilogramme in Asia, stoking lucrative transnational crime networks that have decimated rhino populations in recent decades.

South Africa, which is home to about 80 percent of the world rhino population, has been hit hardest. In 2018, 769 rhinos were poached in South Africa alone. More than 7,100 animals have been killed over the past decade.