The Intellectual Property Crime Unit (PIPCU) of London's Police has drawn another battle line in its war against intellectual property theft with the launch of the Infringing Website List (IWL).

The database aims to provide the digital advertising sector with information about sites that host copyrighted content.

Those found to be hosting copyrighted material will be added to the database and their details passed on to major advertisers.

If an advert from an established brand appears on an infringing website, it lends the site a look of legitimacy.

The hope is once firms find out their content is appearing on websites hosting illegal material, they will pull their adverts from the pirates' pages.

Advertising, according to PIPCU, is a key generator of criminal profits for websites that provide copyrighted content.

Disrupting the flow of this revenue is a major part of the City of London Police's Operation Creative initiative, which held a three-month pilot program last year.

During the trial phase, with the co-operation of the British Recorded Music Industry, the Internet Advertising Bureau and others, 12 per cent of identified illegal websites saw a reduction in major advertising revenue.

"If an advert from an established brand appears on an infringing website, not only does it lend the site a look of legitimacy, but inadvertently the brand and advertiser are funding online crime," said detective chief inspector and head of PIPCU, Andy Fyfe.