A security guard has posted a video which shows him being dragged across the ground as he attempts to stop a small 4WD from leaving the Mangere Town Centre Countdown carpark.
Antonio Tanginoa alleged the group, of three women who had a child with them, had shoplifted.
He described them as being of Polynesian descent.
A police spokeswoman confirmed an investigation into a theft at the supermarket on January 13 at 7:55pm was underway.