And police have warned such tragedies will be repeated this summer if people refuse to wear lifejackets to stay afloat when they fall overboard.

In August, teenager Glen McCulloch died after getting into difficulties swimming in the river near Iffley. The 16-year-old, from Mortimer Road, Rose Hill, was dragged out but died later. Insp Simon Pont, based at St Aldate's police station, said: "Everyone working on or spending time on the water should wear a lifejacket, otherwise more tragedies like this will occur throughout the summer."

In yesterday's accident, the boy was on a boat being renovated by his father.

The child and his older brother and sister were playing inside the boat, none of them wearing lifejackets. His brother went off to buy sweets, the girl played elsewhere - and then the father noticed the younger boy missing. Insp Pont said a "frantic search" took place before police were called at 11.40am and firefighters and ambulance crews were called in.

He added: "People just on Bank Holiday walks saw the activity and rushed to help. They were extremely helpful to police, searching where we said, and they did their utmost to provide maximum assistance in the hunt for the lad.

"When the Mapledurham was moved the boy's body was found at 12.50pm." One person who took part in the search but did not want to be named said: "One feels so helpless - there was nothing we could do to save the little mite. Everyone was crying when the body was found. It seems such a dreadful waste."

The Mapledurham, which usually plies the Thames between Oxford and Abingdon on tourist cruises, has been moved and is being inspected by police, but the boy's death is not being treated as suspicious. Insp Pont added: "It does not matter whether people are working on craft, enjoying days out or just taking part in river activities. They should wear lifejackets.

"This particular one seems to be a very tragic accident and our sympathies are with the parents and the family, who are very shocked indeed.

"Things like this have an enormous impact on everyone, and officers involved in all three emergency services were very affected by it."

Story date: Tuesday 06 April

Converted for the new archive on 30 June 2000. Some images and formatting may have been lost in the conversion.