POLICE were today conducting a grim search for the body of a man who disappeared while trying to swim across a reservoir after a night out with friends.

Mitchell Bury, 33, of Nuttall Street, Ewood, Blackburn, was reported missing after failing to cross Wayoh Reservoir, near Edgworth, early yesterday and police today said he was "missing, presumed drowned."

He had set off to swim the one third of a mile from bank to bank with two friends after a night out in Blackburn.

The two friends, along with two others who had stayed out of the water, went to a nearby house and raised the alarm at about 5am.

Police launched a search of the area using the force helicopter, divers and foot patrols to scour the woodland area surrounding the remote reservoir.

The only trace of Mr Bury was a pile of his clothes, which had been left in a heap by the water's edge, where danger signs warn people not to swim in the deep water.

The Royal Society for the Prevention of Accidents today warned against swimming in open waters such as reservoirs.

Spokesman Jane Eason said: "There were 570 incident of drowning every year -- 320 of them in open waters and those most affected are males aged between 18 and 35.

"I don't know the details of this case but what tends to happen is people go for a few drinks and decide to cool off, especially with the heat wave we are having at the moment. Alcohol does impair swimming abilities and the water is always going to be very, very cold. Even with this weather, it will never be above freezing just a few inches down and people get into trouble as a result."

Police divers called off the hunt at about 7.30pm but were due to begin a fresh search at about 10am today, although police said hopes were fading that Mr Bury would be found alive.Inspector Phil Cottom, of Blackburn Police, said: "Despite a search by the police helicopter and the underwater search team Mr Bury is still missing and there are now grave concerns for his well-being."

Neighbours of Mr Bury, who is believed to live alone, said they were shocked at news of his disappearance.

A next-door neighbour said: "Mitch is a lovely guy and we can only keep our fingers crossed that he has somehow managed to make it out of the water and is still alive somewhere.

"It will be terrible for the family if anything has happened to him, but I'm sure everyone round here will get together to support them."

Police said Mr Bury's mother and step-father, who also live in Blackburn, were too shocked to speak about the incident.

A spokesman for United Utilities said the company owned the reservoir, but access around the edge of the reservoir is a public right of way.

He added: "There are clear danger signs warning that the water is deep and that people should not swim there, that is really all we can do to try to keep people out of the water."

There are life buoys on the road bridge which runs across the reservoir at one end.