The distributors of the latest Lord of the Rings film are angry that some shops started selling the film as early as last Friday.
The film wasn't advertised as going on sale until Tuesday 26 August.
They say stores sold the film early "without their consent".
A spokesman for retail chain HMV said it was one of the last to decide to sell the DVD on Friday.
He also said that other shops' decision to sell the film early could mean problems with getting stocks of future film releases early enough to process.