The Met Police are helping Essex Police in their search for Robert Gurling from Romford, and his son, aged three.
Both were seen at Great Notley near Braintree at about 10.30am on Saturday 2nd of May.
Despite an extensive police search by ground units and the police helicopter, Mr Gurling and the boy have not been traced.
Essex Police have said that Mr Gurling is not allowed unsupervised access to his son and has abducted him from his foster parents.
They say ‘it is imperative that they are located to ensure the child is safe and well.’
Mr Gurling is a 6ft tall white man of medium build in his forties, with cropped dark brown greying hair. He was wearing a grey tracksuit top and jeans. The boy has blonde hair and was wearing a jacket, grey tracksuit bottoms and red trainers.
They may be travelling in a blue car.
DCI Simon Werrett said:
Anyone who sees them should phone 999 immediately. Anyone with less-urgent information about their whereabouts should call Essex Police on 01245 282103.