A picture of an emaciated crocodile sparked concern for its health at a zoo farm in Thailand.

Visitors were shocked when they noticed the frail reptile at the centre in Phichit, central Thailand.

When pictures emerged of the creature, concerned locals complained the local authority amid fears it had been abandoned.

Officials visited the breeding centre, which is also open to the public to view the crocodiles,on Monday where the manager said they were unable to find the crocodile seen in the picture.

Wattana Rewthong, from the region's fisheries department, believes the crocodile is suffering from a disease causing it to lose weight.

He said: "The skinny crocodile is living in one of the farms that are under the supervision of the research centre.

"There are 84 crocodiles in that farm and all of them are fed with chicken weekly.

"However, from the rough examination I believe the skinny crocodile is sick, perhaps because it had eaten some plastic waste thrown into the enclosure by tourists.''

Wattana added that he went to the farm after the case was reported to check on the reptile but could not find it, so he believes it had retreated into a dark place to heal.

He said: "The crocodile might have found a quiet spot in the enclosure to treat itself as that's the natural way a crocodile will handle sickness.

"We will try to find and help treating its illness and reiterate the tourists not to throw plastic into the enclosure."