AceShowbiz -

Dustin Hoffman's "Luck" has brought another bad luck for HBO. After forced to cancel the drama series due to its soft ratings, the network is now sued for allegedly mistreating horses and covering up the abuse.

In her lawsuit, Barbara Casey, who was a director of the American Humane Association's film and production unit, claims she was fired after urging the organization to report the alleged horse abuse on the set of the show. She is suing the organization for wrongful termination.

Casey additionally accuses HBO and Stewart Productions of "aiding and abetting" a cover-up on the said horse abuse. "AHA bowed to political and financial pressure and refused to report the production defendants' conduct to the authorities", the suit reads. "AHA instructed (Casey) not to report such conduct. AHA engaged in efforts to conceal and cover up the production defendants' criminal activities."

She further claims, "In order to save time and money [the defendants engaged in] direct criminal animal abuse and cruelty ... [and] pressured AHA to allow them to violate AHA's safety standards. [And to] allow the use of unsuitable horses in an attempt to ensure that sufficient numbers of horses would be available to meet its production demands."

Responding to the lawsuit, HBO releases a statement to deny the alleged horse abuse. "We took every precaution to ensure that our horses were treated humanely and with the utmost care, exceeding every safeguard of all protocols and guidelines required of the production," the cable channel says. "Barbara Casey was not an employee of HBO, and any questions regarding her employment should be directed to the AHA."

HBO canceled "Luck" in March 2012 following the death of three horses on the set of the sports drama series, which was in the middle of the production for the second season.