Europe's top court on Tuesday said that Google's YouTube and other online platforms are not liable for copyright-infringing works uploaded by users onto their platforms under certain conditions.

The case marks the latest development in a long-running battle between Europe's $1 trillion creative industry and online platforms, with the former seeking compensation or action from the latter for unauthorised works that are uploaded.

YouTube found itself in the dock after Frank Peterson, a music producer, sued the company and Google in Germany over the uploading to YouTube by users in 2008 of several phonograms to which he holds the rights.

In a second case, publishing group Elsevier took legal action against file-hosting service Cyando in Germany after its users uploaded several Elsevier works on its platform Uploaded in 2013 without its approval.

A German court subsequently sought advice from the EU Court of Justice, which ruled on both cases on Tuesday.

"As currently stands, operators of online platforms do not, in principle, themselves make a communication to the public of copyright-protected content illegally posted online by users of those platforms," the EU Court of Justice said.

"However, those operators do make such a communication in breach of copyright where they contribute, beyond merely making those platforms available, to giving access to such content to the public," judges said.

The cases are C-682/18 YouTube and C-683/18 Cyando.