Hampshire Police chief constable Andy Marsh today said Ashya King "needs both medical treatment and for his parents to at his side".
He said: "The situation today is not right."
Ashya King's parents told the Daily Mail they fled the UK after being told NHS treatments would leave him with life-long disabilities.
The head of the police force which applied for a European Arrest warrant against the parents of Ashya King has now urged their release.
A British mother whose son's life was saved by proton therapy has told ITV that she defied NHS doctors' advice to pursue the treatment.