UK police have arrested two individuals on suspicion of selling hard drives containing music and video content worth thousands of pounds.
City of London Police said that the value of the music on just one of the drives was estimated to be in excess of £350,000.
The authorities, supported by Greater Manchester Police, arrested a 55-year-old man and a woman, aged 39, from Bury, after being alerted of the case by the BPI, the UK's music trade association.
Detective chief inspector Daniel Medlycott, head of the Police Intellectual Property Crime Unit (PIPCU), said that it was important the UK's creative industries were protected.
"The vast majority of people who work in the music and film industries are not making vast amounts of money and we have a responsibility to protect the industries they work in."
The accused couple are believed to have been selling hard drives filled with as many as 200,000 files of copyrighted material including music tracks, karaoke tunes and music videos.
The BPI's director of content protection David Wood said music piracy should not be seen as something that is easy to get away with.
"Counterfeiting criminals who believe music piracy is a low-risk activity that carries no penalty are flawed in their views," he said.
"Anyone trying to build a business on the back of someone else's ideas or copyright should ask themselves if making a quick buck at the expense of musicians, local businesses - and indeed their own future - is really worth it."
The PIPCU was launched last year and has just received an additional £3 million in funding allowing it to continue operating until 2016.