Three people were killed when their car overturned on the N3 highway near Estcourt on Saturday, KwaZulu-Natal paramedics said.

Netcare 911's Jeff Wicks said he suspected the driver lost control before the vehicle rolled several times.

"Paramedics who attended the scene found the injured lying strewn at the roadside.

"One man was declared dead on arrival. Another man died while the paramedics were trying to resuscitate him and the last one died on arrival in hospital."

Wicks said two other people who were seriously injured were transported to nearby hospitals.

The actual cause of the accident was unknown.