Ashya King is undergoing his first tests at a clinic in the Czech Republic as doctors prepare him for specialist proton treatment.

The five-year-old was admitted to the Proton Therapy Centre in Prague on Tuesday morning, and will undergo both MRS and CT scans. He will also be fitted for a special mask that will be used throughout his treatment.

If all goes according to plan, the youngster could start the proton therapy on Monday.

The treatment will involve 30 visits and will be combined with chemotherapy, which will be carried out by specialist oncologists at Motol University Hospital.

His father Brett King spoke of his relief. He said: "I am pleased that we are finally here."

Ashya's parents were arrested in Spain after they took him from Southampton General Hospital on August 28 without medical permission.

They were released when prosecutors withdrew a European arrest warrant.

Portsmouth City Council, which previously had responsibility for Ashya's welfare, launched family court action against his parents but Mr Justice Baker, at a hearing in the Family Division of the High Court on Friday, ruled Ashya could be taken to the Czech Republic.

A further High Court ruling on Monday meant he was no longer a ward of court.