Mr Lepper said yesterday he was "gobsmacked" an Auckland man whose son died in a van submerged in Lake Dunstan on Thursday was facing a charge of careless driving causing death.
Mr Lepper was one of a group of men who dived into the lake and tried in vain to rescue the 3-year-boy from the vehicle.
"I think if you'd been on the bank of the lake that day and seen the trauma that family went through, you'd wonder what could be gained by charging the father of that child."
He wanted the charge against the father dropped, he said.
The 32-year-old man, Ashish Macwan, told The New Zealand Herald on Friday he accepted the charge and said the police were doing their job.
He will appear in the Alexandra District Court on Wednesday.
When approached by the Otago Daily Times yesterday to respond to Mr Lepper's criticism, acting Central Otago police sub-area supervisor Sergeant Mike Williams said the matter was before the court, so the police could not comment on any details.
"I can understand the emotion that is involved in this traumatic event for the family, however, police have to look at all of the facts and make an objective decision," Sgt Mike Williams said.
"The police officers dealing with the incident are not immune to the emotion of the incident but they have to be removed from that when they make decisions about this case."
Mr Lepper was at the Clyde Wine and Food Harvest festival yesterday and said his comments reflected "what people have been telling me all day".
"In circumstances where you've been involved in some way and a member of your own family has been killed in an accident, what is the point of imposing any further penalty? What are we trying to prove?
"How did New Zealand get to the point where an accident cannot be accepted as an accident?"
Mr Lepper said he would be lobbying politicians this week and also raising the matter at a meeting of South Island mayors.
"I'd like to see a good round of discussion about whether people think it's appropriate to charge a family member in these kinds of situations. People have already paid the ultimate penalty, so why do the courts have to get involved?
"There's a need for a wider discussion about this, to get people's views. Certainly the people here have been telling me all day they don't think it's appropriate to press charges in these cases."
The child's father was charged six hours after the accident happened, and Mr Lepper was concerned about the timing.
"If he had to be charged, at least give him time to grieve first."
Sgt Williams declined to respond to that comment.
