A Spanish judge is expected to make a decision on whether Ashya King's parents should be taken to Madrid for further legal proceedings tomorrow.
Brett and Naghemeh King were pictured tonight arriving with Spanish police at a court house in Velez-Malaga.
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.