Police are searching for a 5-year-old British boy with a severe brain tumor whose parents took him out of a British hospital and were last seen in France.

The press office for Jehovah's Witnesses said Friday that Ashya King's parents were followers, but that there was no indication that the family's decision was motivated by religious convictions.

Interpol said it was seeking information on the boy's whereabouts. The police body said parents Brett and Naghemeh King removed the boy Thursday from Southampton General Hospital.

French Prosecutor Eric Bouillard of Cherbourg — where they were last seen — said authorities opened an investigation for suspected kidnapping and "failure to carry out parental duties."

Jehovah's Witnesses accept medical treatment, but believe the Bible forbids some treatments and they often refuse blood transfusions.