A company claims it has cracked the anti-piracy technology on Blu-ray discs.
Slysoft says the new version of its AnyDVD programme allows users to make "backup security copies" of high definition movies.
The claim is a blow to Sony which developed the Blu-ray format.
The discs are protected by an anti-piracy system called BD+.
When it launched in 2007, developers boasted it would not be cracked for 10 years.
Sony declined to comment.
SlySoft says it hacked the BD+ technology in November.
It decided to wait for the result of the "format war" between Blu-ray and HD DVD before releasing a full product.
BD+ is designed to react to attempts on its technology.
Its developers say they can re-lock copied discs, making them unusable in the future.
SlySoft reckons it is prepared for this.
Peer van Heuen from the company said: "The worst-case scenario is our boss locks us up with only bread and water in the company dungeon for three months until we are successful again."