Three major record labels have denied signing deals allowing their music to feature on a new file-sharing service offering unlimited free downloads.
Qtrax said it would carry tracks from "all the major labels"
The service, Qtrax, boasted it would carry up to 30 million tracks from "all the major labels".
But Warner, EMI and Universal all say they have not licensed their music.
Qtrax said it expected an agreement to be reached with Warner and that terms had been agreed with the others even if deals had not been formally signed.
Qtrax aims to allow users to download music from the major labels for free, with advertising revenue used to pay licensing fees.
But Warner says it "has not authorised the use of our content on Qtrax's recently-announced service".
And Universal and EMI said discussions with Qtrax were still ongoing but that licensing deals were not in place.
A spokesman for Sony BMG - the other "big four" record label - was not available for comment.
Qtrax president Allan Klepfisz said that, while a deal with Warner had not been signed, he expected terms to be agreed "shortly".
"With everyone else, we have agreed on all terms," he said.
In some cases, deals had not been formally signed, he added.
Online retailer Amazon, meanwhile, has announced the international rollout of its digital music store.
The store, which is already operating in the US, allows customers to download music without any digital copying protection.
Millions of songs will be sold without Digital Rights Management (DRM) software, allowing - for example - customers to burn their own CDs freely.
Amazon says it is the only retailer to offer DRM-free MP3s for the four major record labels as well as thousands of independent record labels.