AN experienced North-East caver and his female companion drowned in a flooded cave system - often used by novices - during a potholing expedition that went tragically wrong.

The bodies of the 33-year-old man, from Darlington, and his 28- year-old companion, from the Bradford area of West Yorkshire, were found following an overnight search by police and rescue teams.

The discovery was made at 3.20am yesterday at the 350ftdeep Alum Pot, near Selside, north of Horton in Ribblesdale, in the Yorkshire Dales.

The alarm was raised at 12.20am by the man's wife after he failed to return home.

She gave police clear directions to where she thought her husband may have gone - and the bodies were located after a threehour search.

Inspector Mike Thompson, of North Yorkshire Police, said: "We responded along with the Cave Rescue Organisation to a report a husband had not returned home. At 3.22am, two bodies were found at a spot known as Lower Long Churn."

The man, who is understood to be an engineer, and the woman had drowned, and police say there were no suspicious circumstances.

A spokeswoman for North Yorkshire Police said the identities of the victims would not be released until Monday at the earliest.

Phil Haigh, duty controller with the Cave Rescue Organisation, which is based at Clapham, North Yorkshire, said the cavers had been caught by rising water in part of the cave known as Plank Pool.

"As far as we know, they were experienced cavers," said Mr Haigh, who led a team of 20 searchers during the incident.

"Over the years, there have been rescues there (at Alum Pot) but it is normally classified as a good introductory cave for novices. It is used over the year by educational and youth groups."

He said that a permanent stream ran through the cavern, which could flood quickly at times.

"The water can rise quickly for a number of reasons, and anyone could be caught out by it," said Mr Haigh.

"A sudden heavy downpour can cause a flash flood or, if the ground is already saturated, water runs over it and fills the caves quickly.

"Whatever caused it, it was a tragic accident and it is particularly poignant at this time of year."

Harry Long, chairman of the Upper Wharfedale Fell Rescue Association, whose team has been called to incidents at Alum Pot in the past, said: "It is a place used by a lot of novice cavers in normal conditions, but it is the route for floodwaters when things turn naughty.

"You can be swept off your feet in a matter of seconds. There are very few caves which do not have that sort of danger, though."

It is understood the area experienced heavy rain during the morning of the caving expedition.

Mr Haigh said the rescuers' thoughts were with the families of the victims.

He said: "Rescue teams are generally made up of the kind of people we help out - we are all cavers and climbers, we all have experience of being in difficulties.

"It means we have great empathy and great sympathy with the bereaved families in situations like this."

Alum Pot was first explored by John Birkbeck, of Settle, North Yorkshire, in 1848, and extends for 1,200ft under the moors.

It is part of an intricate system of caves beneath the western edge of the Yorkshire Dales, which are popular with cavers.

The system includes a cave where a Southampton man drowned during an expedition in March 2005.

In February 2001, Raymond Lea, 58, from Darlington, and Julian Carroll, 29, from Tynemouth, drowned in Ireby Fell cavern, in the nearby Ingleton complex. An inquest heard how the pair were only minutes from safety when they died.

The cavers were discovered suspended from ropes in cold, fast-flowing water after an overnight search by police.

One rescuer said: "In freezing cold water like that, I do not think it would take long to lose complete control of what you were doing and succumb to the conditions.

"It would be a matter of minutes."

In November 2005, Joseph Lister, 14, from Tadcaster, North Yorkshire, drowned in rapidly rising water while exploring Manchester Hole cave, near Pateley Bridge, during a school trip.

An inquest in Harrogate this year heard he was trying to make his way along a passage known as the Crawl with ten pupils and three adults when he got into difficulty in floodwater.

Some of his classmates reached safety using air pockets in the narrow, flooded passage.

Site offers adventure for all abilities

ALUM Pot is one of the classic caves of the Yorkshire Dales, attracting cavers of all abilities and offering excitement and adventure on a spectacular scale.

To the walker passing its entrance, a couple of miles south of the Ribbleshead Viaduct, it is a huge chasm in the fellside down which a river plunges.

To the caver, it is a system of tunnels and shafts that have been worn away by millions of years of floodwaters, and offers what one guidebook describes as "an easy but varied trip with magnificent situations".

There are three ways cavers can get to the bottom of Alum Pot, all offering various degrees of difficulty.

By far the most popular is by the wide and roomy stream passage called Lower Long Churn Cave, the entrance of which is a few hundred yards up the moor from the main Alum Pot chasm.

This delivers the caver into Alum Pot about half-way down the chasm sides, and involves descents of vertical shafts - or "pitches" - using abseiling ropes.

The second route is by Diccan Pot. This is similar to the Lower Long Churn route, but delivers the caver to the foot of the cave system by a series of deep shafts and bypasses the main Alum Pot chamber.

The third route, by far the most spectacular and daunting - and certainly not for the novice - is a direct descent of the Alum Pot chasm. This involves abseiling down vertical walls of dark, dripping limestone into the blackness of the final chamber - about 350ft below.