A three-year-old boy has died after being run over by a ride-on lawn mower driven by his father on the NSW South Coast.

Police are investigating the incident which occurred on Saturday, but say it was likely an accident.

“He reversed over the poor child. He didn’t see it,” a police spokesman told AAP.

Paramedics attended the scene but police say the child suffered catastrophic injuries “not compatible with life” after being hit with the mower blades.

The child was taken to Pambula District Hospital where resuscitation attempts were unsuccessful.

Police are not expected to lay any charges but are required to investigate such deaths to provide a report to the coroner.

“I don’t think anything you could do to the father would change the way he feels unfortunately,” the spokesman said.

“It’s unusual, it’s not a death that’s caused by natural causes, so that’s why we’re doing what we’re doing.”