Life beneath the veneer of The Factory

A photographer recalls the seedy side of Warhol's studio

His photographs of Andy Warhol's studio – known as The Factory – are the defining images of the time. Now a new memoir and previously unseen photographs from Nat Finkelstein are throwing fresh light on the man he described as "Casper the ghost" and the "pack of weasels" who accompanied him.

Finkelstein's memoir, The Fourteen Ounce Pound paints a surreal picture of the musicians, socialites and drug addicts – from Edie Sedgwick and The Velvet Underground to Allen Ginsberg – who camped out in Warhol's Manhattan studio. It mocks Warhol's obsession with fame and reflects on his enduring legacy, the way in which "his aftermath invades our days and ways and enters our souls".

While Finkelstein's photos, taken during his two-year stint as The Factory's "court photographer", were celebrated for their intimacy, his writing is even more revealing. He describes sex with Warhol's muse Edie Sedgwick – whom he once regarded as "the pampered spoiled child of the ruling class" – and claims The Factory destroyed her. "Edie, like many others, was disposable. Like a syringe when its content was dispensed, she was thrown out... left for the bottom feeders, then for the pall bearers," he writes.

In 2006, Sienna Miller starred as Sedgwick in the film Factory Girl, which charted the socialite's rise to fame, and untimely death after a drugs overdose in 1971.

"Nat had a very different perspective on The Factory. He saw it as a decadent group of people. A lot of creative and damaged people," said Finkelstein's widow, Elizabeth. "According to Nat, the antagonism killed a lot of people."

Finkelstein began writing the memoir in 1982, a project which he continued until his death last October. It includes details of the 15 years he spent as a fugitive in the Middle East after fleeing a warrant for drug offences; his involvement with the African-American revolutionary organisation the Black Panthers and life on the Bolivian cocoa plantation where he moved when his drug problem escalated.

Previously unseen images of Warhol, Nico, The Velvet Underground, and behind-the-scenes shots of Factory Girl are on display in the exhibition Nat Finkelstein: From One Extreme to the Other, at the Idea Generation Gallery, in Hoxton, east London.