The artworks once discarded as dump by figurative British painter Francis Bacon are set to go on sale in April. According to Ewbank managers, the company arranging the auction, the 45-lot which include mutilated paintings, photographs, personal diaries and some letters, is a first of its type and could fetch more than an estimated $98,410.

The collection was rescued by Mac Robertson, a former electrician and Bacon's friend. According to a Times Online report, Robertson claims that Bacon allowed him to keep the stuff after he became angry over some workmen who littered his studio's floor with debris.

"I was in the right place at the right time. I had no idea that the bits and bobs Bacon was about to throw away might one day be worth a fortune," Robertson said, according to Times Online.

The items at the auction include a 60-inch by 40-inch portrait, "Study for Portrait," four of the artist's pocket diaries, covering the years between 1966 and 1971, previously unseen photographs of Bacon with his lover Peter Lacy and an vague oil portrait thought to be of a fellow artist Lucian Freud or another lover George Dyer.

Chris Ewbank, an auctioneer of Send, Surrey, said: "Major works by Bacon sell for millions but there has never been a sale like this before so we don't really know what anything will fetch.

"It's unique," he said, according to Time Online reports.

Bacon, much known for his bold, austere and often nightmarish imagery died in Spain in 1992.