A RARE unreleased David Bowie demo track from the 1960s has sold at auction in Chippenham for £18,000 to a mystery buyer.

The track, I Do Believe I Love You, was recorded when Bowie signed as a songwriter to Orbit Music in 1966.

A UK-based phone bidder paid £15,000 plus a £3,000 buyer's fee at the auction at Wessex Auction Rooms in Chippenham yesterday.

The demo was discovered by a London-based seller who found it in a back catalogue collection.

It had been expected to fetch up to £5,000.

Auctioneer Martin Hughes said he believed it to be a "world record" price for an unreleased Bowie track.

"It is exciting for the music world as a whole," he added.

"David Bowie is so iconic that uncovering these these kind of things, it makes you excited about what else might be out there.

"The seller is confident that once he goes through his collection he will end up finding some more because David Bowie was a prolific songwriter."

A signed copy of the singer's 1970 LP The Man Who Sold The World was sold for £7,224 in the same auction of records, guitars and film memorabilia.

Bowie died in January 2016, two days after the release of his final album Blackstar.