Ashya King's father said his son's recovery from brain cancer justifies the family's actions in taking him from Southampton General Hospital without medical consent last August.
He told The Sun: "We have saved his life", adding that they would do the same thing again if they felt they had to.
Ashya King's mother Naghmeh has described news of the boy's condition as incredible.
"If we had left Ashya with the NHS in Britain, he would not be with us today. He was too weak and would not have survived," she told the paper.
Ashya was finally allowed to undergo treatment at the Proton Therapy Centre (PTC) in Prague for brain cancer after a long legal battle fought by his parents.
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