PRAGUE, Czech Republic -- A British boy who caused an uproar after being taken by his parents from a U.K. hospital without doctors' consent landed in Prague on Monday to get treatment for his brain tumour.

Ashya King, 5, was flown to the Czech capital on a medically equipped plane from the Spanish city of Malaga and admitted to Prague's Motol hospital.

His parents, Brett and Naghmeh King, have fought a protracted battle to get their son treated with proton beam technology, which targets tumors more directly than radiotherapy but is not yet available for patients with brain tumors in Britain.

The parents were arrested by Spanish police after they took Ashya from a hospital in the English city of Southampton and travelled to Spain to sell an apartment they owned there to raise funds for the Czech treatment privately. They spend a night in jail in Malaga, but were released after British authorities cancelled the arrest warrant.

The case has ignited a debate in Britain over children's health rights.

Jan Stary, chief doctor at the Department of Pediatric Hematology and Oncology at Motol hospital, said the boy will undergo necessary tests to determine his current condition.

"We know that his condition has been slightly improving in the last few days," he said, adding that Czech doctors have been in touch with their colleagues in Britain and Spain about the boy.

Starting next week, Ashya will remain hospitalized at Motol but will be sent for treatment to a proton therapy centre, Stary said, adding that the therapy should take about five weeks.

"It has been a relatively long time -- six weeks -- since the operation (in England). It's a highly malignant tumour and we have to be certain that the tumour is not growing again or is not spreading. That would modify our decision about the treatment," Stary said.

Ashya's father, Brett, sounded positive after visiting the proton centre on Monday.

"He's got his sense of humour back," he said about his son, who was scheduled to be taken to the centre for a first initial examination on Tuesday.