The grandparents of Émile Soleil have been released without charge, two days after they were arrested over the toddler's disappearance and death in the French Alps in July 2023, reports the BBC.
Philippe Vedovini and his wife, Anne, were among four people detained earlier this week on suspicion of murder and concealment of a corpse.
The other two, both adult children of the couple, were also released without charge on Thursday morning, prosecutor Jean-Luc Blachon confirmed.
Mr Blachon also revealed for the first time that investigators now believe Émile's clothes and remains were transported to the woods where they were found shortly before their discovery last spring.
Mr Blachon added that analysis of the toddler's skull showed traces of "violent facial trauma" which made it probable that a third party had been involved in Émile's disappearance and death.
Until Thursday, one of investigators' working theories was that Émile may have wandered off by himself and died as a result of a fall.
The four people who were taken into custody on Tuesday were released after answering all the questions put to them by investigators, Mr Blachon said, though he added that the line of investigation centred around Émile's family members was not yet fully closed.