This picture highlights the frightening hidden dangers that lurk beneath the surface of the rivers and waterways of Oxfordshire.

The Oxford Mail went out at the weekend to a spot near to where teenager Hassan Hussain tragically drowned while swimming in The River Cherwell in University Parks on Thursday afternoon.

It is believed that Hassan, who was a weak swimmer, got into difficulty because of a sudden drop in the river depth a few feet from the edge of the river.

These photographs clearly show that the water level near the site of the tragic accident was only about four feet deep but just a metre further out it dropped so much that it was barely possible to touch the river floor with a five-metre long punting stick.

In Saturday's Oxford Mail Hassan's father Bashir Hussain gave a heartfelt appeal for members of the public, especially young people and weak swimmers, not to put their safety at risk by going into rivers.

He said: "I would urge people to be very careful and tyake extra care with water. It can be very dangerous, particularly with this hot weather."

Yesterday Mr Hussain's warning was echoed by both the Environment Agency and ther ambulance service.

Chris Mitchell, of the Environment Agency, said: "The difficulty is swimming in rivers is not illegal , we can't stop people we can only make them aware of the risks.

"People shouldn't jump off bridges, that is highly dangerous and they shouldn't swim near boats"

Helen Robinson, spokesman for the South Central Ambulance Service, said: "In light of the tragedy this week in Oxford in which a teenage boy drowned, we are concerned people don't use local rivers and waterways to cool off as they can be extremely dangerous."