Police fear for the life of five-year-old boy with brain tumour taken from hospital by parents http://t.co/R5xRDKeMC8 pic.twitter.com/31KOtjWBeV — Sky News (@SkyNews) August 29, 2014
At a press conference this morning, police said that Ashya had been operated on seven days earlier. Assistant Chief Constable Chris Shead said: "The feeding system is battery operated and that battery will run out today.
"It is vital that we find Ashya today. His health will deteriorate rapidly."
He added: "Time is running out for this little boy. We need to find him and we need to find him urgently."
The spokesman said the boy's life was at "substantial risk" as he needed constant medical care following recent surgery, adding that he was likely in a wheelchair or buggy as he cannot move.
"We are working with our counterparts in France to activate their emergency child rescue alert procedures," he said.
Ashya's brother Naveed King on his profile on the photo blogging platform Instagram describes himself as a Jehovah's Witness.
Jehovah's Witnesses refuse blood transfusions on religious grounds but are open to other medical procedures.
It was unclear what motivated the parents to take their son away.
Additional sources: Sky News