Pop superstar Prince has accused Irish rockers U2 of undermining emerging talent by giving away their music for free.

The Beautiful Day hitmakers caused a storm of controversy when their latest record, Songs of Innocence, was released via technology giant Apple and automatically installed to customers' devices without their permission.

Frontman Bono has since insisted U2 cannot be accused of giving away their music because they were paid by Apple bosses, who then distributed the album free of charge, but Prince, who is a longtime critic of the digital music industry, is adamant the band has damaged the industry for upcoming artists.

He tells the Associated press, "That's a designer deal... Of course they got paid. But what about the others?"

Earlier this year (14), Prince launched his own music publishing company, NPG Publishing, to look after his own work, and that of other artists, and he hopes he can make a difference to up-and-coming acts by getting them a fair deal and proper pay for their work, adding, "I don't want anything from anybody."