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HBO’s canceled series “Luck” has proven to be anything but lucky for the network.

The show was shut down in March 2012 after four horses died in production. Now, a woman who worked with the show is suing HBO, claiming they aided in covering up alleged horse abuse on set for months.

Barbara Casey, who worked for the American Humane Association for 13 years, is suing her former employer, HBO and Stewart Productions, claiming she was terminated after she blew the whistle on the horse abuse.

According to the complaint, filed in a Los Angeles court and obtained by The Hollywood Reporter, Casey witnessed horses being “drugged to perform” and horses that were “underweight and sick.”

In the suit, Casey claims producers ignored the alleged abuse, though she urged them to report it to authorities. She was then fired in Jan. 2012.

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She said the American Humane Association, which had officers working to oversee the safety of animals on set, would not report the abuse due to “political and financial pressure.”

HBO denied any wrongdoing in a statement to The Hollywood Reporter:

"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.”