Olivia Munn is urging bosses behind an online coupon site to "do the right thing" by removing their deals on circus tickets.
The Magic Mike star, an outspoken campaigner for elephants, has urged her fans to boycott Groupon after discovering the discount site was offering cut-price promotions for circuses which features animals.
In a letter to Groupon directors, sent on behalf of People for the Ethical Treatment of Animals (PETA), Munn raises her concerns about the treatment of elephants and tigers made to perform in the circus.
She writes, "I was disappointed to learn from PETA that Groupon is promoting deals with circuses that abuse animals and violate the federal Animal Welfare Act. I was even more disappointed to find out that Groupon was made aware of the egregious crimes of specific circuses yet has chosen to continue promoting them anyway.
"I hope you can see that whether you're an animal lover or not, there isn't a good argument for supporting those who mistreat animals. Elephants, tigers, and other animals who are owned or rented and used by these circuses are robbed of everything that is natural and important to them...
"Most of the circuses that Groupon has promoted have been cited for violations of the AWA numerous times, including in the last two years - so promoting them violates Groupon's own policy. Earlier this year, an elephant handler travelling with one of the circuses that Groupon often promotes was arrested on multiple counts of cruelty to animals.
"Please do the right thing and give animals the 'deal of the day' by permanently severing your ties with circuses that use animals. Until you take this action, I will refuse to purchase deals from Groupon and urge all my fans, friends, and family members to do the same."