Water sewage workers in Kuwait stumbled across the skeleton of what is believed to be a child aged 7-10 years, triggering an extensive police investigation in the oil-rich Gulf nation, a newspaper said on Tuesday.

The workers informed authorities that they had found a badly decomposed body that includes mostly bones and police experts had first determined the skeleton belonged to a newly born baby, Alanba Arabic language daily said.

“Forensic examination later showed the skeleton belongs to a child aged between seven and 10 years,” the paper said.

“The police have launched an extensive investigation to unravel this mystery…security sources said the case could be very complicated if the child’s absence from family has not been reported before.”