Ashya King's parents have been reunited with their child but cannot take him from the Spanish hospital where he is being treated for a brain tumour

It comes minutes after father Brett King said he was being denied all access to his child.

Speaking to a throng of media as he arrived at the hospital, Mr King said: ''Portsmouth have taken the custody away, they won't let me see my child.

''Yesterday they served papers on me to take away the custody so what the Prime Minister said, and the Minister of Health, hasn't worked because me and my wife don't have custody.''

Asked what his next move would be, he said: ''To be arrested, I think.''

Ashya was temporarily made a ward of court last week. But at a hearing in the High Court yesterday Mr Justice Baker expressed concerns that the child was separated from his parents and said he hoped the parents would take part in the next hearing.

No objections were raised during the hearing to the couple seeing their son.

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It comes after Prime Minister David Cameron has criticised the decisions taken by the authorities in how they responded to the removal of Ashya King from hospital by his parents.

Speaking at Prime Minister's Questions Mr Cameron said he didn't doubt that the police, justice and hospital authorities were acting with the best of intentions in trying to locate Ashya, but said he did not think the decisions taken were the right ones.

He said: ''To be fair to the authorities involved in the case of Ashya King, they all want to do the best for the child. That's what they are thinking of.

''But I think what happened was that decisions were taken that weren't correct and didn't chime with a sense of common sense. That, fortunately, has been put right.

''What all of us in public life and public offices have to do is examine what the legal requirements are, but also make a judgment, and those judgments can sometimes be all-important.''.”

Brett and Naghmeh King were freed last night after British authorities abandoned their attempts to extradite them amid a public backlash.

Brett King speaks to the press after being released from prison

And earlier today Mr King said Southampton General Hospital knew he was taking Ashya abroad for treatment before claiming he and his wife were "treated like terrorists".

He said: ''I would be happy to spend years in prison rather than my son being given treatment that's going to kill him or disable him for the rest of his life."

Mr King said he would do the same thing again if it meant getting his son the right treatment.

He said: ''My son's worth everything, worth me going to prison, worth everything because they were going to kill him in England or turn him into a vegetable.''

Mr King described the events since they removed Ashya from Southampton General Hospital as ''not real''.

He claimed he had previously informed the hospital about his plans to seek proton therapy for his son but kept the date that he intended to take him secret for fear he would be stopped.

He said: ''I said to them 'I'm going. The NHS is not going to pay, I've got to sort this out for my son'.''

But he claimed he could not disclose when he planned to remove Ashya because he had previously been ''threatened''.

''I couldn't actually tell them the day because they had threatened me previously,'' he said.

''When I just asked 'What is cancer? How did my son get it? Is there any alternatives?', straight away they said if I ask any more questions the right for me to make a decision would be taken away from me because they get an immediate court paper to say that they have right over my child.

''So from that moment I had so much fear to mention anything to them because they could have stopped my son getting any treatment and just forcing this very strong treatment on him.

''I couldn't tell them when because otherwise they might have stopped me. I was in fear.''

But Dr Peter Wilson, paediatrician at the hospital, said the family did not tell the hospital they would be taking Ashya off his ward.

He said: "The family made it very clear they would like to go to Prague. At no stage did the family say to us they were going to take Ashya out of the hospital."

When asked if the hospital had threatened to take Ashya away from his family, Dr Wilson said: "Absolutely not".

Dr Peter Wilson

They had been held in a Madrid prison after being detained by the Spanish authorities on European Arrest warrants issued in Britain at the request of the Crown Prosecution Service who were acting on information given to Hampshire police by Southampton General Hospital.

Medics have stood by the information they gave to police which instigated the string of events which ultimately led to the imprisonment of Mr and Mrs King.

They said they had a number of grounds to fear that five-year-old brain tumour patient Ashya could be at risk after he was taken by his parents from the ward on which he was being treated on Thursday without the consent of medics.

The Kings are currently on their way to Malaga to be reunited with their son after holding a press conference in Seville where they told of their anguish at being separated from their son.