An obese monkey dubbed Uncle Fatty is feared dead after he went missing from a 'fat camp' in Thailand and has not been seen for the last four months.

The long-tailed macaque was put on a strict diet in 2017 by animal workers, in an attempt to reduce his 33lbs weight - twice the average for an animal of his species.

But their efforts largely failed after he began stealing food from other macaques before vanishing back in February.

A long-tailed macaque nicknamed 'Uncle Fatty' - who was sent to a 'fat camp' after he ballooned to 33lbs eating sugary treats thrown by tourists - is likely dead

Uncle was last seen back in February, and experts say he likely took himself away from his troop in order to die

He developed an enormous belly before wildlife officials who received reports from concerned locals and decided to intervene

They believe he got fat because tourists kept feeding him food and drinks that were high in calories, which also reduced the amount of exercise he did because he did not need to forage.

After his disappearance locals asked police to check CCTV footage from areas he was known to roam in, but turned up no sign of him.

Further searches have also been unable to locate his body around the Khun Kala Monument where he was a pack leader.

Superstitious locals believe that the lack of a corpse adheres to a legend that the forest 'reclaims' the bodies of the monkeys, but others fear he has been eaten.

Kavinaphat Mongkoltechachat, the president of the We Love Monkey Club, said: 'Our staff always saw him sitting in front of the monument every time they came to feed the pack. But one day, he was just gone.

'We thought that he was just sick and might have gone into a deep forest to heal himself. We decided to search there the following week but still couldn't find him.'

Thai primate conservation group 'Monkey Lovers' said today that Uncle was not sick - he was just fat after being fed a diet of treats

Monkey Lovers Organiser Kawinoat MongKholtechaphat said that Uncle played an important role among monkeys that roam free around the market in the Bang Khun Thian district

The Thai primate conservation group said that Uncle just really likes to eat and had gorged on 'everything that people give to him'

When Mongkoltechachat asked monkey specialists to speculate on what could have happened to Uncle Fatty, all of them said it was likely the twenty-year-old monkey was dead.

He added: 'They told me that when monkeys know that they're very weak, they will isolate themselves and won't let any other monkeys or anyone see them dying.

'He might have died of old age because Uncle Fatty has already lived beyond the age average. He also looked exhausted and didn't want to eat much.'

'We'll keep searching for him because we're still worried about him. It might be sad if we discover that he really is dead but it's better than not knowing anything at all.'

The National Parks, Wildlife and Plant Conservation had transferred Uncle to a Nakhon Nayok wildlife rescue center some 100 miles away where he will receive health checks

Thailand is home to hundreds of thousands of wild monkeys including gibbon, macaque, langur and loris, that roam free and are popular with tourists

Health workers had attempted to make uncle move around more in order to reduce his weight, but to no avail

Thailand is home to hundreds of thousands of wild monkeys including gibbon, macaque, langur and loris, that roam free and are popular with tourists.

They often co-exist with human populations, and are known to steal food in order to survive.

However, they can also be an attraction for tourists and many - Uncle Fatty included - have worked out that they are more likely to had over food.

Among the many items fed to Uncle Fatty were thought to be sugary melons, milkshakes, sweetcorn and noodles.