A MAN has died after taking part in a swimming challenge in a lake.
The 52-year-old was taken to hospital by air ambulance following the incident during the Great North Swim in Windermere, Cumbria Police confirmed.
The force said: "At 4.40pm today police at the event were alerted to a man who was taken by air ambulance to the Cumberland Infirmary, as a result of a medical emergency.
"The man, aged 52, from Wallington, sadly died."
The man's death is not being treated as suspicious and the coroner has been informed, police added.
The Great Swim Series is the UK's biggest exhibition of open water swimming and is staged in clean and safe lakes, lochs and docklands in various areas of the country, according to its website.
The Great North Swim was being held in Windermere today, tomorrow and Sunday and features half-mile, one-mile, two-mile or 3.1- mile courses, with "expert safety kayakers" accompanying swimmers.
The man, who has not been named, was from Wallington, south London, police confirmed.
The event's organiser, Nova International, released a statement, expressing its condolences.
The statement said: "Nova International deeply regrets the tragic loss of life at the Great North Swim today and offer our deepest sympathy and condolences to the family and friends of the individual concerned.
"In the case of a fatality there is a strictly planned procedure that we adhere to with the professional organisations. We must ensure that the next of kin are informed before any further comment is made but we will provide an update as soon as we are in a position to do so."