David Cameron has said "common sense in the end won out" after five-year-old Ashya King was finally reunited with his parents.
Speaking on Good Morning Britain, the Prime Minister said: "Having had a disabled child often in hospital, often fed through a tube those pictures absolutely meant so much to me.
"The thought of having your much-loved boy separated from you for all those hours and days I can't think of anything more painful for a parent."
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.
The parents of Ashya King said they took him out of a hospital to seek proton beam treatment which is not available under the NHS.