Chinese netizens took to social media to demand Lin Hui, a female panda currently kept at Chiang Mai Zoo, be returned to China, following the recent death of her mate Xuang Xuang.

On Weibo, China's popular platform, a social media user said Thailand is "not suitable for raising pandas", while another said that Thais "do not treat animals as well as we think", the BBC reported.

One widely shared image, whose source is still unidentified, claims to show Xuang Xuang being fed hard bamboo stems instead of bamboo leaves -- sparking further uproar among Chinese netizens, who then demanded the remaining panda at Chiang Mai Zoo be returned to China.

Xuang Xuang died at the age of 19 on Monday. A panda's average life span in the wild is 14-20 years. But they can live up to 30 years in captivity.

Veterinarians at Chiang Mai Zoo said the panda died of old age, dismissing an unsubstantiated report which claimed that a "white object" was found in Xuang Xuang's windpipe.

A check into Xuang Xuang's parents lifespans showed that neither had lived to old age. 

Experts from China will conduct a post-mortem examination on the panda later on Thursday.