Nicole Richie claims a paparazzo did the unthinkable at LAX ... he dropped his own kid on the floor so he could whip out his camera and get a shot -- and then she shamed the guy on Instagram.
Richie posted the photos a couple of hours ago ... claiming the man -- not a TMZ guy -- "dragged his poor, sweet little girl on my plane from NYC to LA."
She continues, "As he ran her off the plane, he dropped her ON THE FLOOR of LAX as she laid there, crying her eyes out.. Just to get his shot. #Heartbreaking #FatherOfTheYear."
In fairness to the photog, there are no photos showing the snapper actually dropping the kid on the ground.
But if N.R. is telling the truth ... what a d-bag.