Joseph Mabuza, the spokesperson for Mpumalanga's safety and security MEC Pat Ngomane was killed in a crash on Sunday, a colleague said.
"It is so sad," said the premier's spokesperson Zibonele Mncwango.
Mabuza is understood to have been travelling on a motorbike near the Lebombo border post on Sunday afternoon when a vehicle made a u-turn in front of him, and there was a crash.
Mncwango said Premier Refilwe Mtsweni and all of Mabuza's communications colleagues were shocked by the news.
"The premier is saddened by this sad news," said Mncwango.
"He was the best man," he said.
One of Mabuza's last Twitter posts was, ironically a plea for road safety with the simple words: "Let's not die on the road".