SURABAYA, Indonesia  - A male giraffe that died in an Indonesian zoo was found to have 20 kilograms of plastic in its stomach, officials said Saturday, the latest suspicious animal death at the facility.

Kliwon, 30, was born at Surabaya Zoo, the biggest in the country, and was its last remaining giraffe, living alone in its pen for 13 years. It died on Thursday.

“We got the autopsy results last night. They found a plastic lump weighing around 20 kilograms and 60 centimetres in diameter in his stomach,” zoo spokesman Anthan Warsito told AFP.

The giraffe was also found to be infected with tuberculosis.

“We have a staff of around 180, and seven of them have tuberculosis, so it’s possible one of them transmitted it to the giraffe. At this point we don’t really know the cause of death,” Warsito said.

The plastic probably came from food wrappers the animal ingested after visitors tossed them into its pen over several years, Warsito said.

The incident comes after a spate of suspicious animal deaths at the zoo, including a critically endangered Sumatran tiger, and the disappearance of three baby Komodo dragons believed to have been stolen for the black market.

Warsito said that around 500 animals had died between 2010 and 2011.

The zoo was criticised in 2010 when its then management attributed hundreds of animal deaths to treatable ailments, including pneumonia, diarrhoea and malnutrition.

Last year, the Forestry Ministry revoked the former management’s licence.

“We have plans to buy two or three new giraffes from America, but we have to see what management says after this incident,” Warsito said.