Placed on a bridge over the river, flowers have been laid for the teenage boy, who was with two friends at the time.

Members of the public flagged down officers at around 5.30pm on Friday (June 27) as one man attempted to rescue the boy but could not find him.

The boy's body was found in the water at about 6:40om after an "extensive search" involving police, fire and rescue, ambulance crews and the National Police Air Service.

Thames Valley Police say the boy’s death is being treated as unexplained but not suspicious. 

Superintendent Emma Burroughs described the death as a "complete tragedy".

Ms Burroughs said: “This has been an extremely traumatic and upsetting incident, and despite the best efforts of emergency services at the scene, we were unable to rescue the boy, who was with two friends at the time.

“I am aware that a member of the public entered the river shortly after the boy got into difficultly, but was unable to locate him.

“I would like to commend him for his courage and bravery.

“My sincere condolences are with the boy’s family and friends, and I would ask that their privacy is respected at this incredibly traumatic and distressing time for them.”