A drug-addled crossdresser has been arrested for allegedly stealing a newborn baby from a hospital in Thailand.

Nantajak Silprasert, 43, walked into the Bang Len Hospital in Nakhon Pathom before dawn on August 13 and snatched two-day-old Thanadech from his bed while his mum was sleeping.

He was seen carrying the infant out of the building in a black plastic bag, which he hung on the handlebars of his getaway motorcycle.

Mother Yuparat Tesnam, 26, said she had breastfed the child before falling asleep at 3:30 am but woke up 30 minutes later only to find her baby missing.

She told the boy's dad Phongsathon Thampinit, 28, who reported the suspected kidnapping to the Bang Len district station.

Officers said they received a tip about the culprit at 11:00 am and pinpointed Nantajak's residence to a house in Tambon Hinmoon.

They rescued the baby and returned him to his parents and are now investigating if Nantajak is involved in a human trafficking ring.

Police Captain Uthit Laoha of the Bang Len Police Station said: 'We are expanding the investigation to see if the suspect is connected with other kidnappings. It was also found that he has multiple bank accounts and is deep in debt.'

Officers said Nantajak was a crossdresser had a history of drug use and was giving 'confusing' testimonies during interrogation.

Police Colonel Adisak Kamnerd, superintendent of the Bang Len Police Station, said: 'The suspect said he took the baby believing it was his own child. Later, he claimed that he had taken the baby because he was unable to have one of his own.'

Nantajak's mother said she became suspicious when he opened multiple bank accounts, adding his strange behaviour may have been from stress due to a failed business venture.

Meanwhile, baby Thanadech underwent check-ups at the Bang Len Hospital, but was transferred to the Nakhon Pathom Hospital when he was found to be suffering intracerebral haemorrhage, cerebral oedema, a swollen eyelid, a severe infection, and hypoxemia. He was prescribed an anticonvulsant for at least a year, and will be monitored closely by doctors at the hospital.

Dr Kamonlak Jindatrairat, director of the Bang Len Hospital, said he has met with the child's parents to discuss compensation.

He said: 'We are very sorry and apologise for what happened. The hospital has security measures in place, but we believe that the suspect had surveyed the hospital buildings beforehand. That's why he knew how to avoid the hospital staff.'

He added that the hospital is planning to increase security by hiring more security personnel and implementing a key card system.