John Lennon's widow Yoko Ono has blocked the screening of a US documentary about the ex-Beatle.
The makers say the film gives a unique insight into Lennon
3 Days in the Life uses film taken two months before the band split in 1970.
Executive producer Ray Thomas set up a free screening at a private school in Maine because he could not get Ono's permission for a commercial screening.
But Ono said she had a copyright interest in the film and any screening would breach copyright. The school said it still hoped to host the film.
The footage was shot by Ono's former husband Tony Cox and was sold in 2000 for $1m (£760,000) to Mr Thomas and his backers.
Among other things, Lennon is seen composing songs, touring his 100-acre (40-hectare) estate and rehearsing for a BBC show in which he performed Instant Karma for the first time publicly.
There is no commentary and all action is unscripted, but the makers say it offers a unique insight into Lennon's creative process.
Hap Ridgway headmaster of the Berwick Academy, said: "What we've learned since it all broke loose is that it's a long-running dispute."