The NHS Trust that treated Ashya King has claimed it had agreed to refer the five-year-old for proton radiotherapy, as requested by his family, before he was taken from hospital.
A spokesman for University Hospital Southampton NHS Foundation Trust said it believed Ashya had a "very good" chance of survival with standard radiotherapy.
The spokesman added that the family were told that proton radiotherapy would have no difference in survival and no proven significant benefit.
Despite this, the Trust agreed with the family to refer Ashya for proton radiotherapy, as the family had indicated that they could fund it privately. On 28 August 2014, during unsupervised leave on the Trust’s grounds, Ashya’s family chose to remove him without informing or seeking the consent of medical staff.
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.