Mourners' vehicles crashed into each other "like dominoes" after a police officer pulled over the hearse leading the cortege near Te Anau.
Police have launched an internal investigation after the Te Anau policewoman ordered a hearse to pull over as it led a cortege of between 80 and 100 cars to the Te Anau cemetery last week, causing nose-to-tail crashes behind.
Three vehicles were damaged, two of them extensively, resulting in the policewoman having to ferry some mourners back to Te Anau.
There was speculation the incident was the funeral director's second brush with Te Anau police, who pulled him up for speeding en route to the town, the Southland Times reported.
This has been denied by the funeral director.
A son of the dead man, who was in the car behind the hearse, was "bloody furious" with police.
"I thought it was absolutely disgusting," he said.
"Here we are taking dad to the cemetery and we are all pulled over and there are accidents behind us. It was just like dominoes."
He said he could not understand how the policewoman could not know it was a funeral procession, and he wanted her to pay for the damage to the cars.
Southland police boss Inspector Tony O'Neill yesterday declined to comment on the incident, saying it was under investigation after a complaint was laid with police.
The funeral director, who asked not to be identified, said he had been travelling about 70km/h on the open road leading the cortege.
The hearse's lights were on, as were the lights of the 80 to 100 cars behind him.
The policewoman, parked on the opposite side of the road, had gestured at him to pull over, the funeral director said.
Three cars further back in the cortege crashed when it was brought to a halt.
Waipahi man Gerard Vallely, who was in the middle of the pile-up, estimated his speed at between 30km/h and 40km/h.
Mr Vallely said he managed to drive his car back to Te Anau but the occupants of a badly damaged Land Cruiser were taken back in the police car.
Mr O'Neill said it could be "some weeks" before the investigation was completed.