Ashya King's father has thanked those that worked to ensure the release of him and his wife from prison this evening.
Brett King told reporters outside Soto del Real prison near Madrid he had not known the extent of the public support as they had been unable to watch television in prison.
"I have to go and see my son," he then said before getting into a car.
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.