Harrowing footage captured inside an infamous Thai zoo has exposed the cruelty that its animals are forced to endure.

Traumatised elephants are shown rocking their heads from side to side in a sign of 'psychological distress' while tethered to short chains, crocodiles swim in dirty rubbish-strewn pools, and agitated tigers are fed by guests using meat on a stick.

Campaigners are urging tour companies to stop taking visitors to the Samut Prakan Crocodile Farm and Zoo, south of Bangkok, after animals were repeatedly recorded in poor conditions.

This week Ctrip, China's biggest online booking agency which owns the likes of Skyscanner, officially cut ties with the zoo after an investigation by charity PETA.

Activists are urging tourists not to visit Samut Prakan Crocodile Farm and Zoo, south of Bangkok, after it filmed animals being mistreated there

Elephants were seen tied up on inch-long chains while swinging their heads in what campaigners said was a sign of distress

Bears were also seen rubbing up against the side of their dirty container, described by experts as nervous behaviour caused by their surroundings

National Geographic also investigated the same facility, and found a four-year-old elephant Gluay Hom which they said was emaciated, had a limp leg that he was refusing to stand on, and a large sore on the side of his head.

Meanwhile an ageing tiger named Khai Khem was seen was a dental abscess so severe that it was eating through his jaw.

When contacted, owner Uthen Youngprapakorn said the fact that both animals were still alive was proof they were being cared for, then threatened to sue.

In December last year, footage also emerged of an emaciated elephant being forced to perform tricks in front of a deserted stand at the tourist attraction.

Despite the growing pressure from activists, the zoo continues to operate and animals are still in appalling conditions.

Elephants were stabbed with sharp objects in order to make them perform for crowds, including standing on raised platforms while tourists walk underneath

Crocodiles were left to swim in algae-covered and rubbish-strewn pools of water at the zoo

Tigers were taunted with pieces of meat on sticks that tourists used to feed them through holes in the bars of the cage

Footage taken last week shows traumatised elephants chained up while rocking their heads from side to side in a sign of ''psychological distress''.

They are then lead into an area where they are forced to stand on one leg, kick footballs and throw bowling balls at rows of skittles.

Holidaymakers can place tips in their trunks, pose with them for pictures, and walk under their massive bodies.

The treatment seen in the video has been criticised by animal welfare groups.

PETA announced yesterday that Ctrip would now stop selling tickets to the zoo and called on other tour operators to follow.

Spokesman Jason Baker said: ''Ctrip did the right thing in nixing tickets to this despicable, abusive, brazen operation.

'PETA is calling on all travel companies still offering excursions to such facilities to follow Ctrip's compassionate, business-savvy example and strike exploitative businesses from their itineraries.'

The elephant is made to walk over to rickety wooden tables before standing up on both of them - although the stadium behind is empty

PETA said that the 'zoo handlers jabbed elephants with sharp metal spikes and forced them to give rides and perform tricks such as bowling, painting, and dancing.'

The charity said that the elephants could not interact with each other and 'continuously swayed back and forth, a symptom of psychological distress.'

The zoo also houses Asian Black Bears - which were filmed scratching nervously against the side of a concrete pool.

Crocodiles are also kept in cramped enclosures and swim in filthy ponds, while tigers and gorillas spend their days in tiny cages.

The Samut Prakan Crocodile Farm and Zoo declined to comment when called Tuesday from Bangkok.

NASDAQ listed Ctrip was founded in 1999 and provides travel services including accommodation reservation, transportation ticketing, packaged tours and corporate travel management.