A man has died and four people are in hospital following suspected "substance abuse" at a music festival.
Police were called by staff at Cumberland Infirmary just before 7am today over a man who had arrived from the Kendal Calling festival in a critical condition.
He was later pronounced dead.
A 29-year-woman from Bolton, Greater Manchester, is in a critical but stable condition, while three men are described as being in a serious but stable condition.
A spokeswoman for Cumbria Police said: " Emergency services are currently dealing with an incident where five people have taken ill following believed substance abuse at the Kendal Calling festival. "
The spokeswoman added: "An investigation has commenced into the circumstances surrounding his death. Police are supporting the deceased's family at this time.
"Police have arrested a 20-year-old man from Manchester on suspicion of possession with intent to supply. He is currently being detained for questioning.
"Anyone with any information is asked to contact Cumbria Police on 101 or alternatively you can call Crimestoppers on 0800 555 111."
The four-day festival at Lowther Deer Park in the Lake District began yesterday and headline acts this year include Snoop Dogg, Elbow and Kaiser Chiefs.