The National Musical Publishers' Association (NMPA), a major body in the US music industry, has joined the case to sue YouTube. It claims that some of its songwriters are not being sufficiently compensated when their music appears on the site.
While the four major record labels have reached agreements with YouTube allowing the site to carry their music in exchange for a cut of the advertising revenue, most music publishers have not, reports the Wall Street Journal (WSJ).
Responding to the development Google told the paper: "Many songwriters and music publishers view YouTube as a promising promotional platform for connecting with their fans. We are surprised and disappointed that the NMPA has elected to take this route."
Other companies currently suing the search engine Google's video sharing service include Paramount pictures and Comedy Central.
YouTube has denied liability, saying it has remained within the law by removing clips discovered to be in breach of copyright.
Google recently announced that it is in the process of developing advanced "fingerprinting" technology that will enable the detection of copyright infringing material that is uploaded onto the site.
However, some media companies remain sceptical about the new technology with Louis Solomon, a lawyer at Proskauer Rose LLP, telling the WSJ that he believes it is a stalling tactic.
The search engine took over YouTube in October last year in a stock-for-stock transaction.
