5 Year Old Ashya's parents want him to have Proton Beam Therapy, what is it?

Brett and Naghmeh King are being held in custody in Madrid - while a court considers a British extradition request.

They were arrested after a Europe-wide police search located them in Malaga with Ashya.

Ashya's parents want him to be able to receive proton beam therapy which is only available on the NHS for eye conditions.

Proton beam therapy is an expensive specialist treatment and not currently available on the NHS.

Although Mr and Mrs King have appeared in Spain's high court - they have not been charged with any offence.

Dr Clive Peedal - a consultant clinical oncologist at James Cook University Hospital in Middlesbrough, is familiar with proton beam therapy, and explains to Neil Green about the limited facilities available in the UK.