Howard Blank, a spokesman for the River Rock casino resort in the Vancouver suburb, confirmed an incident took place Wednesday evening.
Global TV reported Richards was filming a scene for the movie "Blonde and Blonder" when she allegedly confronted a photographer trying to take her picture. Richards threw the laptop computers off a balcony, hitting two elderly women sitting in the lobby below.
Paramedics were called but the women did not appear to be seriously injured.
"Based on the actions of the paparazzi, they are lucky their laptops were the only things that were thrown off the ledge," Richards' publicist, Nicole Perez, said in Los Angeles on Thursday.
A statement from "Blonde and Blonder" producer Dean Bornstein indicated that a "number of unauthorized persons" got onto the set and began "harassing members of the cast."
"While trying to stop the paparazzi, Denise Richards was involved in an altercation," Bornstein said. "To protect her safety she instinctively knocked the paparazzo's laptops off a ledge. Royal Canadian Mounted Police were called to the scene as a precaution and the case was soon closed. No charges were filed against Ms. Richards."
Richards, 35, has appeared in appeared in the movies "Wild Things" and "Starship Troopers."
She has two daughters, Sam 2, and Lola, 1, from her marriage to Charlie Sheen, who stars in the CBS sitcom "Two and a Half Men."