Waimate police are urging the driver of a car involved in a crash near Morven to contact them.
Six members of a family sustained minor injuries when the driver of their northbound car took evasive action to avoid a car heading south on State Highway 1 near Horsnells Rd on Sunday night.
Constable Tim Shearer said the southbound car had pulled out to overtake a milk tanker about 7pm.
The driver of the other car had swung off the road to avoid a head-on collision.
The car rolled nose-to-tail several times, and the members of the family were "very, very lucky'' to escape serious injury.
Const Shearer said the driver of the milk tanker later spoke to the female driver of the car which allegedly caused the crash, but did not get the vehicle's registration.
"It's possible the woman does not actually realise there was a crash,'' Const Shearer said yesterday.
