Yoko Ono is celebrated today for her career in art and music, but it's easy to forget that she was also vilified back in the 1970s not only for her purported and much-discussed role in the Beatles' break-up, but her role in the break-up of John Lennon's first marriage.

A newly-discovered open letter written by Lennon to Cynthia Twist (as she was later known) and published in a magazine in the 1970s, is going up for auction and gives the former Beatle's side of the story in their divorce.

Lennon wrote the letter in response to a tell-all book that Cynthia had written, called 'A Twist of Lennon'.

It began:

"Dear Cynthia,

As you and I well know, our marriage was over long before the advent of L.S.D. or Yoko Ono… and that’s reality! Your memory is impaired to say the least. Your version of our first L.S.D. trip is rather vague, and you seem to have forgotten subsequent trips altogether!”

He also advised his ex-wife to "try to avoid talking to and posing for magazines and newspapers!” if she wanted to escape her 'Beatle past', and accused her of "asking me to remarry you and/or give you another child, ‘for Julian’s sake’!” while he was separated from Ono. “I politely told you no, and that, anyway, I was still in love with Yoko", he wrote.

The letter - which is estimated to sell for more than $25,000 - ends: "We did have some good years, so dwell on them for a change and, as Dylan says, it was a “Simple Twist Of Fate”!”