Lying in a makeshift bed, Huynh Van Dat is heard wailing.

His thin hands are seen clutching at his emaciated chest, where his ribs are visible through his sagging skin.

But most shocking of all is his face, which is green and rotten with gangrenous flesh.

Dat's face has been slowly eaten away by a mysterious disease, which has claimed the roof of his mouth, his cheeks and his eyes.

The 51-year-old, from Saigon, in southern Vietnam, can no longer eat and can barely talk.

Huynh Van Dat, 51, contracted a mysterious disease which is eating away at his face. It has claimed the roof of his mouth, his cheeks and his eyes

In a video taken by local media, his tongue is seen moving through the crater in his face, and he is clearly in agonising pain.

MailOnline has chosen not to show the video due to its distressing nature.

After the heartbreaking story appeared in the press, top doctors in the country have agreed to take on his case.

Dat's wife, Huynh Thi Trieu, said although he could no longer eat properly or speak, he was still of sound mind, and he was well aware of the horrific fate he has been suffering since symptoms began 11 years ago.

Trieu, who is also 51, said her husband's condition first presented itself in 2004, when he began getting nosebleeds three or four times a day.

She said: 'He was taking traditional medicines but they didn't make any difference, and then he also started to have problems with his eyes which were constantly watering.'

Dat went to Hoa Hoa Hospital in Saigon to be examined.

Doctors realised there was a problem with his nose partition which was diagnosed as a deviated nasal septum, and which they operated on.

Dat cannot see and can barely talk or eat. His wife says despite the mystery disease being incredibly painful, the family are too poor to take him to hospital

After Dat's story was reported in the local press, top doctors in Vitenam have agreed to take on his case

But it did not seem to slow the pace of the disease - and a year later Dat discovered whenever he drank water, it ran into his nose through a hole in the roof of his mouth.

Several months later, the hole got bigger and Dat had further surgery after the bridge of his nose collapsed - but this also failed to help.

Despite being told another operation could solve the problem, he could not afford all medical treatment that was required.

There is no bleeding, but when he could still talk he had told us it was incredibly painful Huynh Thi Trieu, 51, Dat's wife

When his funds ran out, he returned home and tried to get by using traditional medicine based on herbs he could find locally.

His wife said: 'The disease, which started with a hole in his nose, simply grew and it ate his nose, upper jaw and his eyes.

'There is no bleeding, but when he could still talk he told us it was incredibly painful.'

Now blind, Dat spends his days lying in his makeshift bed.

While he can barely talk, he still has the ability to touch and hear.

Despite his dire condition, Dat's wife says the family are now too poor to take him into hospital,Vietnam.net reports.

But after the story and pictures were published in local media, a team of medics visited him and promised to do what they could to help in order to ease his suffering.