BANGKOK • Experts from China have arrived in Thailand to investigate the death of a beloved giant panda, zoo officials said yesterday, as millions of Chinese netizens questioned the cause of the male bear's sudden demise.

Nineteen-year-old panda Chuang Chuang, a resident of Chiang Mai Zoo since October 2003, died on Monday after years of living in an air-conditioned enclosure with female Lin Hui.

The pair were on loan from the south-western Chinese city of Chengdu as part of Beijing's so-called "panda diplomacy" and were supposed to be returned in 2023.

Pandas can live up to 30 years in captivity and Chuang Chuang's sudden death has raised questions about his care.

China "urgently dispatched panda experts" to investigate the cause of death, Chiang Mai Zoo said in a statement, and a Chinese-Thai "joint working team" will perform an autopsy.

Thailand has long obsessed over Chuang Chuang and Lin Hui, as the notoriously sex-shy pair had struggled to conceive and were shown video clips of successful panda couplings to stir their libidos.

Thanks to artificial insemination, Lin Hui finally gave birth in 2009 to Linping, spurring a widely watched live 24-hour "Panda Channel".

Chuang Chuang's death sparked expressions of concern for Lin Hui on China's social media platform Weibo, with the hashtag, "We want Panda Lin Hui to come home".

"The countries that rent giant pandas can keep them if they raise them well, or else they should send them back," said Ningbo Ni Shao, a local media outlet.

The Chinese consulate in Chiang Mai, a city in northern Thailand, on Wednesday released photos on its website of Chinese and Thai officials mourning Chuang Chuang, placing flowers by a framed photo near the zoo's entrance.

AGENCE FRANCE-PRESSE