AN investigation is underway after a man in his 20s is thought to have drowned in an East Lancashire reservoir.

Emergency services were involved in a four-hour search at Ogden Reservoir, in Barley, after receiving reports that a young man had entered the water and may have got into difficulties, just before 5pm yesterday.

Helicopters from Lancashire Police and the North West Ambulance Service (NWAS) were deployed, alongside a Lancashire Fire and Rescue Service drone.

Rossendale and Pendle Mountain Rescue Service also assisted with the search, which ended in tragedy at around 9pm with the discovery of a body in the water.

An inquiry has now begun into the how the young man, who has not been named, came to be in the water.

The alarm is thought to have been raised by a second man, who had become concerned after he had not seen the first man for some time, after he went into the reservoir.

A Lancashire Police spokesman said: "We were called at around 5pm yesterday to Ogden Reservoir in Barley to reports a man had got into difficulties in the water.

"Emergency services attended the scene and a search was launched.

"Sadly at around 9pm the body of a man, thought to be aged in his 20s, was located in the water.

"At this point his death is not being treated as suspicious and a file will be passed to the coroner in due course."

A Lancashire Fire and Rescue Service spokesman said the swift water rescue boat, from Nelson station, was launched, alongside a specialist rescue craft from Penwortham.

While extensive searches were made of the water, members of the emergency services also conducted a comprehensive sweep of the nearby banks.

A spokesman for NWAS said a rapid response car and an ambulance were dispatched to the scene, just before 5pm. A number of other specialist units were also deployed later.

The remote reservoir, owned by United Utilities, is only been accessible by a single track.