U.K. dance label Ministry of Sound says it will continue to pursue illegal uploaders of its repertoire, despite a blow to its campaign to target individuals and seek compensation.

Ministry of Sound has put on hold its campaign, launched in the summer, to pursue uploaders and seek out of court settlements. The company halted the process after it discovered that leading ISP BT has deleted more than 20,000 records of customer activity that Ministry of Sound had asked them to save pending a legal hearing.

Since July, Ministry of Sound has been applying to the High Court to require ISPs to provide customer data of illegal uploaders the label has identified.

Ministry of Sound said it has sent over 5,000 warning letters and settlement notices requiring suspected uploaders to confirm the unauthorized activity and pay £350 ($564) or risk legal action. The company said a large proportion has settled.

The campaign was undertaken by lawyers Gallant MacMillan and DigiRights Solutions, who identified more than 150,000 U.K. IP addresses from where Ministry of Sound's content was uploaded.

Last month BT challenged this process following a security breach of customer data in a separate case and was granted a stay of execution in the High Court. BT said it requires clear evidence of infringement before handing over customer details.

According to Ministry of Sound, legal correspondence has revealed that 20,000 of the 25,000 records have not been preserved. The legal costs of the case would not make it economically viable to pursue just the remaining 5,000 identified uploaders, according to a statement, so Ministry of Sound has put the campaign on hold.

Ministry of Sound chief executive, Lohan Presencer, said: "We are more determined than ever to go after internet users who illegally upload our copyrighted material. We will be making further applications for information from all ISPs. Every time that a track or album is uploaded to the Web it is depriving artists of royalties and reducing the money which we can invest in new British talent."

BT said in a statement: "All such information is automatically deleted from our systems after 90 days in accordance with our data retention policy; the Ministry of Sound and its solicitors are well aware of this. Upon request from Ministry of Sound we saved as much of the specific data sought as we reasonably could and any not preserved must have been too old. Our door remains open to Ministry of Sound and any other rights holder who wants to enforce their rights in a fair way through an established legal process."