The parents of five-year-old cancer patient Ashya King have said they do not feel safe to return to Britain.
Brett and Naghmeh King are set to travel to Spain after their son's proton therapy treatment came to an end.
Asked why he was reluctant to return to the UK, Mr King said there was "so much still at stake" and did not want to risk losing Ashya.
"At the moment we don't feel 100% safe, I suppose you would call it, contemplating being in England until perhaps they do this investigation into how everything was conducted for us," Mr King told Sky News.
"Once that has been established then we can think about going back to England. But for the time being we have been in contact with a doctor in Spain so we are continuing with (Ashya's) treatment in Spain instead of England."
The parents of five-year-old cancer patient Ashya King have released images of their son after he finished proton therapy treatment in Prague.
Brett and Naghmeh King sparked an international search when they removed Ashya from Southampton hospital in August without medical consent.
The family are now preparing to leave for Spain after the youngster's condition improved.
Doctors at the Czech proton therapy centre where Ashya King is being treated for brain cancer, have said he has responded well to treatment. The 5-year-old from Portsmouth was removed from Southampton Hospital by his parents earlier this year, sparking an international search.
Ashya King is due to start proton beam therapy in the Czech Republic today to treat his brain tumour.
The five-year-old from Southsea has been in the country for the last week for consultations.
His parents - Brett and Naghemeh King - took him out of Southampton General Hospital last month after a disagreement about his treatment.
"In my personal blog, I will keep you up to date on what is happening at the Trust, sharing what I think we are doing well and what we can improve.
When I was woken last Thursday night by a phone call from the duty exec to tell me that a child had gone missing, I didn't anticipate that the hospital would spend the next week and a half at the centre of an international media storm.
I know that everyone shares my relief that Ashya is now in Prague Motol Hospital, where he will be able to receive the treatment that he needs.
"At times over these recent, very intense few days, I have been left lost for words, but one of our emergency department consultants has written two 'tweets' that express my feelings better than I could myself
The first read as follows:
Of all medical specialities paediatric oncology must be one of the hardest. Young lives, devastating diseases, special doctors and nurses."
He is so right. During the past week I have got to know some of the Southampton paediatric oncology team very well. I have been humbled by their compassion, fortitude and forensic attention to detail under pressure. When their email inboxes were full of personal abuse from strangers, and there were journalists camped on their front door, they were still worrying about how we could do the best thing for a small boy in Spain.
I cannot imagine having to face the reality of your child being diagnosed with a brain tumour. But I do know that in this dreadful situation, I would want the support and care of this brilliant clinical team.
The second tweet said:
Whilst the country's media looked for its next scoop @UHSFT today continued to provide top quality evidenced based care to its patients."
I know how hard this was on some days last week. Our switchboard and patient support services were overwhelmed with calls from irate members of the public. Our security team were busy trying to manage multiple camera crews and satellite vans, the clinical site team were attempting to maintain control of the situation alongside all the usual challenges of bed availability and our press team were besieged by the media, whilst trying to make measured judgements about how to respond to this unprecedented situation.
And many other people working here were being questioned by patients or the public about this situation, sometimes in a very aggressive way.
But through all of this we still had thousands of patients who needed care and treatment. And I'm so grateful to everyone who kept on doing their job, and making sure that we gave the best possible patient care that we could. Thank you so much to everyone for this. Thank you in particular to people who took on extra work to cover the usual work of their colleagues (like me!) who were trying to manage this particular issue. You have made me proud, once again, to be part of University Hospital Southampton."
Ashya's father Brett King described his incarceration as "torture" for the five-year-old.
Mr King and his wife were in jail for five days while Ashya was in Spain, but he said their discomfort was nothing compared to anyone who had cancer.
Mr King said Ashya is still traumatised after the enforced separation: "Every time I say goodbye to him, he starts to cry: 'will I see you tomorrow?' sort of thing," he added.
Mr King also told media waiting outside the Proton Treatment Center in Prague that he is concerned about what authorities will say when his other children do not attend school in the UK.
Most of the King family remains in Spain.
Video: Five-year-old Ashya King has arrived with his parents at the Proton Therapy Centre in Prague.
Ashya King could start proton treatment as early as Monday, the Proton Therapy Center in Prague has said.
In a statement the centre said that the five-year-old had been fitted with a special treatment mask today as well as undergoing a series of tests.
If all goes well and the physicists will be able to prepare Ashya’s irradiation plan in four days already instead of standard ten days, he will start the first irradiation on Monday. His plan takes 30 irradiation visits and is combined with chemotherapy. The chemotherapy will be applied by specialised oncologists at Motol University Hospital, where Ashya is hospitalized with his mother.
The father of brain tumour patient Ashya King - who was taken from hospital in Southampton without the consent of doctors - will meet doctors in Prague to discuss his potential proton treatment. Brett King is due to visit the Proton Therapy Centre Czech after his five-year-old son left the Materno Infantil hospital in Malaga in Spain. Ashya has been treated there since his parents were arrested more than a week ago.
Five-year-old brain tumour patient Ashya King has left a hospital in Malaga and is believed to be heading for specialist proton therapy treatment in the Czech Republic.
Brett King, Ashya's father, was seen travelling in a taxi behind the ambulance carrying his son.
Mr King and his wife Naghmeh removed Ashya from Southampton General Hospital on August 28 against doctors' advice, following a disagreement over his treatment.
They were arrested in Spain but British prosecutors withdrew an international arrest warrant and they were released three days later.