PEOPLE are being warned about the dangers of swimming in reservoirs after police and fire crews searched for a woman who they feared may have drowned after skinny dipping in a Nelson reservoir.

The woman and two men had been swimming in Walverden Reservoir in the early hours of Saturday morning.

Police were called to the scene by local residents, who heard shouting.

When they arrived they found a distressed, partially clothed man who was concerned about a woman he had been swimming with.

But following a two-hour search of the area by police and firefighters she was found, also partially clothed, at a nearby cottage.

A police spokesman said: "We believe her and a third male had been skinny dipping in the reservoir. She had got out for a cigarette and when she saw the police she panicked because she didn't want to be found and disappeared.

"We had searched for some considerable time to find her and we were concerned that she may have drowned."

One man was taken to hospital to be treated for the symptoms of hypothermia and the female was checked out by an ambulance crew but refused hospital treatment. She was taken back to her home address.

A spokesman for United Utilities today said: "This incident is a stark reminder of the danger of swimming in reservoirs.

"They are deep, extremely cold and the undertows caused by drawing off the water into supply mean even the strongest of swimmers can quickly get into difficulties.

"We would ask everyone to stay away from the water at reservoirs, however tempting it may seem during hot weather.

"If you want to swim, use a properly supervised swimming pool."