SAN FRANCISCO – Two women who helped care for a famous gorilla have sued the foundation nurturing Koko, saying they were fired for refusing to show the animal their breasts, lawyers said on Friday.

The lawsuit says the president of the Gorilla Foundation, Francine Patterson, sought to have the women bond with the gorilla by performing “bizarre sexual acts with Koko.”

“Through sign language, as interpreted by Patterson, Koko ‘demanded’ plaintiffs remove their clothing and show Koko their breasts,” the lawsuit said.

“Patterson pressured plaintiffs to perform such acts, regularly and consistently, and on at least one occasion, outdoors where others could see,” the lawsuit added.

The Gorilla Foundation, south of San Francisco, maintains that Koko understands a sign language vocabulary of more than 1,000 words. Some experts believe that claims to understand a gorilla so well are exaggerated.

According to the Gorilla Foundation’s Web Site, Patterson is a “real-life Dr. Dolittle” who has worked more than 30 years communicating with Koko, who was born in 1971. Patterson did not return calls, but her attorney issued a strong denial.

“We unequivocally deny these allegations and are confident that this case lacks merit,” Todd Roberts said in a statement. “For the attorney for plaintiffs to manipulate a purported employment issue and miscast it purely for publicity purposes is particularly hurtful to the noble efforts of such a reputable organization.”