Task to clean old packages on specific repository

Our CI system (TeamCity) build two type of branches for our npm packages : Develop and Master (simple gitflow process nothing special).
After each correct build CI deploys on two different repository/feed on nexus server: Nightly Feed and Stable Feed.

What we just would like to have is a task to remove old packages on Nightly Feed because packages number is so high. What we found is that a separate feed for nightly is the only way to delete in one shots all nightly and reduce server space requirements.....so right now we just delete feed and recreate it every month.