Parents of the missing 8-month-old baby boy were separately questioned by Bang Luang police in Nakhon Pathom province for about nine hours on Tuesday, as a sewage pump truck was sent to their house to empty the septic tank in the search for the infant.

Suspicion grew that the parents, 18-year-old Sitthichoke Sangsawang and 16-year-old Pilaiporn, might be responsible for the disappearance of their baby after a neighbour told the Bang Luang police today (Wednesday) that he went to the couple’s house, which is also a grocery, and found the baby, the couple and a 12-year-old niece were at home on Sunday, when the baby is reported to have gone missing.

Other neighbours have also told the police that they did not see any strangers in their neighbourhood, who might have kidnapped the baby, as conjectured by the couple.

In an interview with Thai PBS reporters, the couple denied that they have sold or fatally harmed their own baby and expressed hope that the police will be able to find him.

Officials from the Hin Moon Tambon Administrative Organisation (TAO) sent a sewage pump to the couple’s house, after police found traces of newly-laid cement around the toilet pedestal.

A relative of the couple told officials that she laid the cement about a month ago, but the TAO officials went ahead and emptied the septic system. They did not find anything suspicious.

Police and officials from the Mirror Foundation continued their search for the missing baby for the third consecutive today, but have stopped using a sniffer dog.

In addition to the couple, all their relatives have been questioned by the police.