More details have been emerging in the Belgian media about the mystery surrounding the death of a four-year-old boy whose body was found in Zeeland on Monday evening.

It now transpires that the Dutch girlfriend of Dave De K, the Belgian national who babysat for the boy and who was arrested near Utrecht, has also been picked up.

De K is suspected of kidnapping the child and having a role in his death. The girlfriend, known by the initial R, faces more serious charges of kidnapping and murder, although this may be to do with the different legal systems, Flemish broadcaster VRT said.

De K and his girlfriend regularly looked after the boy and his sister, aged seven. His mother Elke Verberckmoes told Belgian media that she had great faith in De K, who she described as caring towards her son.

Last week she called in the couple to take care of Dean because she was unable to do so for medical reasons. According to Belgian media, she is undergoing outpatient hospital treatment for depression.

Grandparents

The couple were due to take the child to his grandparents but girlfriend R told the boy’s mother that Dean wanted to spend another night with the couple, then another.

On Saturday Verberckmoes discovered that the couple had had an argument and that De K had left at least a day earlier, taking the child with him. He is also now thought to have spent Saturday night in Koudekerke in Zeeland, where he was spotted by a neighbour, without the child.

Belgian and Dutch police are cooperating closely on the investigation, De Morgen said, and the focus is largely on what De K did while he was in the Netherlands.

De K was jailed for 10 years in 2008 for his role in the death of his then-girlfriend’s two-year-old son.