SURABAYA, Indonesia (AP) — A 12-year-old endangered orangutan has become the latest animal to die at Indonesia’s problem-plagued largest zoo, officials said Thursday.

The female orangutan, Nanik, was found dead Sept. 21 in a quarantine facility at the Surabaya Zoo in East Java’s capital, said zoo spokesman Agus Supangkat. Her appetite dropped in the last two months, and she was moved two days earlier for intensive treatment of liver and intestinal disorders.

"There was a liver disorder and a bump in its intestine," said chief veterinarian Liang Kaspe. "But whether it was cancer or not, we have to wait for the results of the pathology test."

Nanik was brought to the zoo seven years ago by a local conservation agency after being confiscated from an illegal owner. Her death leaves nine orangutans — three males and six females — at the zoo, Kaspe said, adding that three of those orangutans were born at the facility.

Supangkat says on average about 20 animals die monthly at the zoo from various causes.

A giraffe died there last year with a beach ball-sized wad of plastic food wrappers in its belly, sparking outrage among conservationists. An African lion, a bear and several crocodiles have also died at the zoo.

The facility, built under Dutch colonial rule nearly a century ago, has been plagued by uncontrolled breeding, a lack of funding for general animal welfare and suspicions that staff members may be involved in illegal wildlife trafficking. It was taken over by the city administration in July, after years under a government-appointed temporary management team.