Wicked composer Stephen Schwartz is working on a new film "within the world of Oz".

The 77-year-old composter has confirmed he and Winnie Holtzman — who wrote the book for the iconic Broadway musical and served as a co-writer on its big screen adaptation — have started work on another project set in the same universe, which was originally presented to him before either Wicked or Wicked: For Good had been released.