The male and female who died at the scene of a crash at Mataura in Southland yesterday were back-seat passengers, say police.
The pair were among five people to die in a horror weekend on the country's roads.
Welch confirmed the unofficial road toll now stands at 24 for the year, the process that follows a fatal crash would take a month before that figure was confirmed.
At the same time last year that number was 23.
Welch urged drivers to wear their seatbelts, drive sober, keep their phones away out of reach, stick to the posted speed limit and not to drive distracted.