Pamela Anderson penned a letter to M.A.C. owner and friend John Demsey expressing he disappointment in the brand for testing on animals.

The longtime cruelty-free brand admittedly tests on animals where it is "required by law," like China.

According to the New York Post, the former M.A.C. spokeswoman and PETA activist said she "was so proud to be a Viva Glam M.A.C. girl in 2004...But the buzz is much different now, and you know I can't bite my tongue."

The actress said she first found the cosmetics brand -- owned by Estée Lauder -- to be "very progressive and forward thinking."

"That's why I was very disturbed to learn from PETA that M.A.C., under your direction at Estée Lauder, is selling products in China, where the company funds painful tests on animals in order to meet the country's archaic regulations," Anderson said. "This has tainted the brand and alienated many of the company's longtime allies."

"As an honorary director of PETA and a former M.A.C. spokesperson, I urge you to pull out of the Chinese market until the country's testing methods are modernized like those of much of the rest of the world. Corporate leaders can make this happen," she said.

"Won't you restore M.A.C. to its former glory as a brand with principles?"

M.A.C.'s parent company released a statement acknowledging the accusations, maintaining their pride for being "one of the first cosmetic companies to establish that cosmetic safety can be demonstrated by non-animal testing methods," but saying they still have to play by the rules regarding international trade.

"Before we are able to import any of our products to China, the Chinese government requires all importers of cosmetics, including us, to pay for animal testing that is conducted by a government-mandated laboratory in China," the statement reads.

The brand does not show signs of wanting to pull their products out of China, even after news of its practices overseas went public, and after its former spokesperson publicly urged the company to do so in her letter.

"As a global company, we are committed to providing our products and services to our consumers where they live, and we must comply with all legal requirements in the countries where we do business," Estée Lauder said.

Still, the company says it is fighting to end animal testing of cosmetic products and lists several programs it is supporting to reach the goal.

"As a Company, we conduct or commission only in vitro and human volunteer testing to establish the safety and efficacy of our products -- and we will continue to diligently advance the acceptance of the existing alternatives to animal testing everywhere we sell our products," they said.