A monitor lizard left residents horrified when it was found gnawing on the corpse of a newborn baby in Thailand.

The beast was seen feasting on the remains of the child who was abandoned at a housing estate in Samut Prakan, just outside Bangkok, on November 28.

Shocked neighbour Thanakorn Niamnuch, 52, said he was taking out the rubbish when he spotted the giant reptile tearing into a small object in an empty lot nearby.

He said: 'At first I thought it was just a turtle, but when I went to take a closer look, I saw it was a baby's body. I shouted for the neighbours to help, and we chased the monitor lizard away before calling the police and rescue team.'

Police arrived at the DD housing estate at around 1:30 pm local time, where they discovered the infant's body lying near the gap of a house foundation.

Cops said a foul stench permeated the area as the newborn had already been ravaged by the reptile, with organs strewn across the area.

A torn red thermal bag stuffed with a large stone, believed to have been used to weigh it down, was found nearby. Officers said the baby had been left in the bag.

While forensics officers were collecting evidence, the scavenging monitor lizard was seen emerging from under the pavement and trying to drag the dead baby away.

Police Colonel Pojjanakorn Kanjina, superintendent of Phra Samut Chedi Police Station, said: 'We are investigating if there were any recently pregnant women in the area and are working to review CCTV footage.

'The child's body has been taken to the Institute of Forensic Medicine for a post-mortem examination.'

Officers later arrested the mother, View, 19, along Rama IV Road in Bangkok, and she was detained.

Despite her baby being fully formed when it was found, View said she was not aware that she was pregnant, as she claimed she had continued to have regular menstrual cycles.

The young woman, who works for a local cleaning service, claimed she gave birth 'after slipping during a shower'.

She reportedly told police: 'After I stood up, I saw blood running down my thigh, and then the baby fell onto the bathroom floor. I was shocked and speechless. I didn't want my family to find out, so I used scissors to cut the umbilical cord and quickly cleaned up all the blood.'

View added that she then stuffed her baby and a stone weight into the thermal bag before dumping it under another person's house.

Police boss Pojjanakorn said: 'We have interrogated the mother and released her. We will now wait for the autopsy results from the Institute of Forensic Medicine, which should take less than 45 days, to determine whether she had caused the baby's death before summoning her to face charges.'

In May, another monitor lizard was found eating a newborn baby in the same province.

Shocked locals called police when they saw the 7ft creature scampering around the grassy wasteland with the infant's remains in its jaws at a housing area for Burmese workers.

Officers later recovered the baby's head and torso. Authorities believe it had been born around two days earlier before being killed and eaten alive by the ravenous reptile.

Monitor lizards are a common predator in Southeast Asian countries. However, they usually feed on fish or small snakes and rarely attack humans.