Many people heard that filming of the HBO series "Luck" was canceled when four horses died.

The Hollywood Reporter just published a stunning investigation suggesting this is just the tip of the iceberg of animal abuses occurring in the film world.

The American Humane Association (AHA) is the group that watches over animal welfare and awards films and TV shows the "no animals were harmed" moniker. They send representatives to watch over filming of movies and TV shows.

While the AHA once played a huge role in making Hollywood safer for animals, many recent incidents suggest that their work today in inadequate. Even those within the AHA who spoke to the Hollywood Reporter have lost hope in their role.

But the problem, according to the article, is that the AHA's flexible application of the "no animals were harmed" credit leaves plenty of animals harmed. Notably, the credit doesn't apply during hiatuses in filming, when the harm wasn't intentional, or if the harm happened when the cameras aren't recording.

Here are some allegations made in the investigative report:

During New Zealand filming of Peter Jackson's "The Hobbit: An Unexpected Journey," 27 animals reportedly perished. According to the Hollywood Reporter, sheep and goats died from dehydration and drowning during a filming hiatus.

A trainer punched a Husky dog repeatedly in its diaphragm on Disney’s 2006 Antarctic sledding movie "Eight Below," starring Paul Walker, after the dogs got into a fight on set.

A chipmunk was fatally (and accidentally) squashed during the production of Paramount’s 2006 "Failure to Launch."

Potentially because crew members on Disney's "Pirates of the Caribbean: The Curse of the Black Pearl" had taken no precautions to protect marine life when setting off special-effects explosions in the ocean, dozens of dead fish and squid washed up on shore for days.

In March, a 5-foot-long shark died after being placed in a small inflatable pool during a Kmart commercial shoot in Van Nuys.

Two horses died during the filming of Fox's "Flicka," which the AHA claims were accidents. This film didn't get a "no animals were harmed" credit but a credit that said the "American Humane Association monitored the animal action." So now you know what that means.

In 2010 during the filming of the Hallmark Channel's "Everlasting Courage," a horse named Glass was fatally injured when he was stabbed by a small broken part of a runaway wagon. He was euthanized. [See the somewhat disturbing injury on Glass's leg]

Four horses died during the Luck filming's between 2010 and 2012 Read the full story on Luck here »

During the filming of "The Chronicles of Narnia: Prince Caspian," many horses were removed from production because of injuries – up to 14 at one time. But, the production recieved a "No Animals Were Harmed" disclaimer.

A report on equine performers from 2001 to 2006 concluded that 82 horses had been adversely affected while working on sets during this period, including 58 injuries and eight deaths (from things like a "collision with camera car," "stepped on lead rope," and "impalement").

Multiple horses died from colic (potentially triggered by heatstroke) on the set of "There Will Be Blood" from Paramount Vantage. The AHA gave the film a modified end credit that stated that they "monitored the animal action.”

Read Animals Were Harmed at the Hollywood Reporter »