Witnesses told LOOP PNG, the deceased, a male and a female were thrown off the back of the maroon land cruiser at different times when the driver lost control at a dangerous bend near Manugoro village, causing the car to slip and roll twice down a slope.
"The female was thrown in the first flip. She died instantly when her head hit a rock," witnesses said.
"The male was tossed onto the bitumen road in the second flip and died instantly."
There were six people in the car, three females and three males, all from the Highlands.