LONDON (AFP) - A British judge in the case of five-year-old cancer patient Ashya King formally lifted his ward of court status in London Monday as the boy arrived at a Prague hospital for treatment.

Judge Jeremy Baker also described the treatment proposed by his parents Brett and Naghmeh - who took him from a British hospital to Spain in a disagreement over treatment, sparking an international manhunt - as "perfectly reasonable".

Ashya has now been admitted to hospital in Prague where he is expected to undergo proton beam therapy following surgery to remove a brain tumour in July. This is a type of radiotherapy which is not generally available in Britain but causes less damage to surrounding, healthy cells.

Ashya's treatment was being funded by a combination of his parents, donations from the public and a social fund administered by the family's Spanish lawyer, the judge indicated.

"The course of treatment proposed by Mr and Mrs King is entirely reasonable," Baker told the High Court, calling them "loving parents".

"Any parents in the position of Mr and Mrs King would do whatever they could to explore all options."

British local government officials had acted "entirely correctly" in applying for the boy to be made a ward of court based on the information they received from Southampton Children's Hospital, the judge said.

While he declined to comment on whether it had been wise for British police to apply for a European Arrest Warrant for the parents, Baker noted that it was "not in his (Ashya's) interests to be separated from them" for four days when they were arrested and taken into custody.