The two men, believed to be part of a large syndicate, were booked on a Qatar flight destined for Hanoi, Vietnam, from Maputo.
The aircraft made a one-hour scheduled stop at the Johannesburg airport last night, during which the passengers were initially expected to remain inside the aircraft.
But passengers were later asked to exit the flight and proceed to the international departures area as authorities had received information through crime intelligence that there would be two men travelling with the horns.
Police spokesperson Solomon Makgale said 18 horns were discovered in the suspect’s bags.
“This is the largest haul of rhino horns seized in one operation in South Africa. It is believed that these horns were removed from rhinos in South Africa,” said Makgale.
It is believed that the rhino horns seized may have been taken from rhino in the Kruger National Park, but tests and analysis on the horns would verify this.
“Detectives investigating this case will now be looking for the South African connections forming part of the international syndicate,” said Makgale.
He added that the operation had dealt a serious blow to the illegal rhino horn trading industry, but that police hoped to snag the big fish as well, and not only the runners.