Pressure is mounting on the owners of a Chinese shopping centre after a million people called for its polar bear tourist attraction to be shut down.

Pizza, dubbed the 'world's saddest polar bear', is confined to a small enclosure without natural light and air in the Grandview Shopping Mall, Guangzhou, south China.

Disturbing footage of the three-year-old bear made headlines around the world last month. She was seen slumped on her side with her mouth quivering, as animal experts warn she must be relocated.

Pizza, dubbed the 'world's saddest polar bear', is confined in a small enclosure without natural light and air in the Grandview Shopping Mall, Guangzhou, south China

Hundreds of thousands of visitors come to the Chinese centre each year to see Pizza

Animal experts are concerned about Pizza's behaviour inside her small enclosure

Hundreds of thousands of visitors come to the centre each year to see Pizza.

Now one million people have signed two petitions calling for the mall's animal enclosures, which contain 500 different species, to be closed.

Last month, Doncaster's Yorkshire Wildlife Park, offered to give the polar bear a home in its 10-acre enclosure.

However, it is understood that the Chinese authorities have refused the offer, stating that Pizza will not leave China.

The Grandview's general manager was reported as stating that there is 'no need for foreign organisations to get involved'.

Not to be deterred, China's own animal groups have taken up the campaign.

In an open letter to governor Zhu Xiaodan, 50 Chinese animal groups are urging him to take action.

The groups are asking that the animals, including arctic fox, walrus and beluga whales, be rehomed as soon as possible.

The Chinese groups are adding their voice to the international outrage at the polar bear’s fate, as new undercover video footage is released by Humane Society International (HSI) and its Chinese partner group VShine.

Professor Alastair Macmillan from HSI viewed the footage and said: 'This polar bear is showing classic stereotypical behaviour, including head swaying and repetitive pacing, induced by frustration and poor welfare.

Shopping centre managers have said they will improve her conditions but will not expand the enclosure

Disturbing footage of the three-year-old bear made headlines around the world last month

'This is the animal's attempts to cope with stressful, aversive situations such as barren enclosures, boredom and constant disturbance by visitors.

'The conditions in which he is being kept are completely unsuitable, vastly removed from anything approaching his natural habitat, and if something is not done then he will likely slip further and further into mental decline.'

HSI, along with Care2 and Born Free Foundation, has collected 500,000 signatures calling for the closure of the mall’s enclosures, in addition to the 500,000 signatures previously collected by Hong Kong-based Animals Asia Foundation.

The shopping centre's management has denied claims about the polar bear enclosure.

Li Chengtang, the deputy general manager, said the reports give a false impression of the venue.

He denied that animals are kept in poor conditions, but admitted Animals Asia's attention has prompted them to give the facilities a boost.

Pizza can't be released into the wild because she was born in captivity, but they have come up with a 'polar bear enrichment plan' to improve life for the animal.

Live fish will be put in her pool for her to chase and food will be frozen into ice blocks to challenge her.

She will also be given sporadic access to an area out of view from customers.