A tourist has been caught throwing a plastic bag filled with popcorn right into the mouth of a hippo at a zoo in China.

Footage of the incident shows the man laughing when he saw the animal swallowing the plastic bag and the popcorn.

The unidentified visitor had disobeyed the zoo's rules and climbed onto the fence of the hippo enclosure in order to feed the animal, according to Nanchang Zoo.

The man in China throws a handful of popcorn towards the hippo which is opening its mouth

He then chucks the whole bag of popcorn towards the hippos while sitting on the fence

The incident took place in Nanchang, a major city and the capital of south China's Jiangxi Province.

The man's act was captured on a video, which was uploaded onto China's social media platform Weibo yesterday.

Weibo user 'tu dou chao rou a' called the scene 'heart-breaking' and the man's behaviour 'abominable' in the post.

The net user, believed to be at the scene, said the man threw popcorn, the popcorn's paper container as well as a plastic bag used to carry the snack right into the hippo's throat.

The user also claimed that the man had brought along his child to the zoo.

The Nanchang Zoo has reported the man to the police after being alerted of the incident by the net user.

The zoo has three hippos: 14-year-old male 'A Ya', nine-year-old female 'Jing Jing' and one-year-old male 'Hua Hua'. It is unclear which hippo was fed.

After the hippo swallowed the food and the plastic bag, the man smiles in satisfaction

The incident took place in Nanchang Zoo, China, which has a total of three hippos (file photo)

In an online statement today, the zoo condemned the man's 'uncivilised' behaviour.

The man had apparently ignored nearly 1,000 signboards around the zoo, which warn tourists not to feed the animals or to climb onto the fences. Among them, 14 are placed at the hippo enclosure.

Plastic bags can be extremely harmful to animals.

Each plastic bag takes about 1,000 years to break down. Once it is ingested by an animal, it cannot be digested or passed by the animal. This means the plastic bag stays in the animal's guts, which can lead to the animal's death.

According to UNESCO, every year plastic debris causes the deaths of more than a million seabirds and more than 100,000 marine mammals.

In May, 2015, three deer died at Shanghai zoo after eating plastic bags by mistake.

Nanchang Zoo said it had asked vets to examine the hippo, and the animal showed no abnormality so far.