Ashya King's parents have been pictured after their release from custody, and offered thanks to the public for their support.
The couple's lawyer earlier said they would speak about at a news conference in southern Spain - the region where Ashya is being treated - tomorrow.
The National Court in Madrid said in a statement that a judge had ordered the couple's immediate release.
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.