He and a friend, also aged 16, were swimming in a stretch of the river near Lower Hampton Road, Sunbury, during the hot weather on Sunday.

The boy got into difficulties in the water - his friend called for help and was aided by someone in a passing boat.

Surrey police and fire services were called soon after midday. They pulled the boy from the river, but he later died at St Peter's Hospital, Chertsey.

Police said it appeared the boys were trying to swim across the river.