Glastonbury: A close friend of the British prime minister was found dead in a portable toilet at one of the country's leading music festivals on Sunday, authorities said.

Christopher Shale died in unexplained circumstances in the VIP area of the Glastonbury Festival, an entertainment extravaganza that's one of the fixtures of Britain's music calendar.

Shale, who was in his 50s, chaired the Conservative Association in David Cameron's West Oxfordshire constituency, and in a statement Cameron said he and his wife Samantha were devastated by the news.

"He was a great friend and has been a huge support over the last decade," Cameron said. "A big rock in my life has suddenly been rolled away ... like so many others Sam and I have lost a close and valued friend."

Shale was staying in a restricted, celebrity-packed area of the festival, which is held on a farm in southwestern England and has drawn some 170,000 people.

He was discovered by police shortly after 9 a.m. Festival organizer Michael Eavis said he was told the incident was "a suicide situation" but police have yet to confirm that.

"It is only a couple of hours ago," Inspector Chris Morgan said. "We are still working on establishing a cause of death."

News of the death comes the same day as Shale was quoted in a national newspaper as describing the weakness of his association in unusually frank terms.

"Over the years we have come across as graceless, voracious, crass, always on the take," the Mail on Sunday quoted him as saying in a strategy document which the paper said it had seen.

According to the Mail, he added that people weren't joining his group because they "think we'll beg and steal from them. And they're right."

Tags: Christopher Shale, Conservative Association, David Cameron, Glastonbury Festival, UK PM's friend