Hampshire Constabulary has launched a search for Theo, aged 17.
He was last seen on November 21 in Horsham, West Sussex.
READ MORE: Bexhill man dies in A259 car crash outside Custom Cafe
Police believe the teen travelled to Hampshire, where he has been seen frequenting Southampton town centre and the surrounding estates.
He is described as black, six foot tall and of slim build.
According to police, Theo was last seen wearing a green North Face puffer jacket, black jeans and black Nike trainers with white soles.
A force spokesman asked any residents who think they have seen Theo or know where he is now to contact them immediately on 101 quoting 44240512338.
