The world's oldest giant panda in captivity, Jia Jia, has died at a Hong Kong theme park at the age of 38, the equivalent of 114 human years.

The female panda was euthanised on Sunday night, following rapid deterioration in her health over the past two weeks, said authorities of Ocean Park, the Hong Kong theme park that was home to Jia Jia, in a statement.

Her food consumption had drastically fallen over recent weeks, from 10 kg a day to under three, leading to a four kg weight loss, EFE news reported citing the statement.

"Over the past few days, she has been spending less time awake and showing no interest in food or fluids. Her condition became worse this morning (Sunday), Jia Jia was not able to walk," the statement further said.

Jia Jia, whose name meant "good", was a gift from the Chinese government to Hong Kong in 1999, on the occasion of the second anniversary of the former British colony's handover to the mainland.

The average life expectancy for pandas living in captivity is under 20 years, making Jia Jia's longevity unique among her species.

According to the World Wildlife Fund, the destruction of the natural habitat of the giant pandas in the wild has reduced their population to less than 2,000.

Their low birth rate also means breeding in captivity has become key to ensuring its survival.

While Jia Jia was in Hong Kong, she had six offspring, spread over five deliveries.