A poem about a dead dog which was thought to have been written by Bob Dylan, was actually a song by late Canadian country singer Hank Snow.
Auction house Christie's had expected the handwritten verse, called Little Buddy, to fetch up to $15,000 (£9,660) in a memorabilia sale next month.
But in a statement the auction house said: "The words are in fact a revised version of lyrics of a Hank Snow song."
Dylan had signed the lyrics under his original name - Robert Zimmerman.
It is thought he wrote the song down at the age of 16, during a stay at a Wisconsin summer camp in 1957.
However, Christie's maintain the two-pages could still be worth something as the song sheet "remains among the earliest known handwritten lyrics of Bob Dylan".
Dylan wrote the piece for Herzl Herald, which was the summer camp's newspaper.
Fellow camper and editor Lisa Heilicher kept the handwritten original, but has decided to sell it, to help raise funds for the project.
"I kept it with all of my stuff that I collected from camp," she said.
"When I realised how famous he had become, I put it in a piece of plastic and stuck it in an encyclopaedia."
Christie's pop culture specialist Simeon Lipman had previously described the lyrics as a "very early example of his brilliance".
He added: "It comes from the mind of a teenager [with] some very interesting thoughts kind of percolating in his brain."
Several other pieces of Dylan's writing are being offered at the pop culture sale, including lyrics to With God on Our Side.
The song, which appeared on the musician's third album, The Times They Are A-Changin', has been estimated to sell for up to $25,000 (£16,121).