Find Completed Tasks in the Web Rest API

How can I find the completed tasks for a case via the Web Rest API? I can find a ready task here

http://localhost:8080/bonita/API/bpm/task?f=caseId%3d3052

and view the task here:

http://localhost:8080/bonita/API/bpm/task/60182

But once the task is completed I can no longer find it directly or find it in a search. This is what I expect, however I cant find any way of retrieving completed tasks for a a case.

I have tried using the archivedTask endpoint:

http://localhost:8080/bonita/API/bpm/archivedTask/60182

http://localhost:8080/bonita/API/bpm/archivedTask?f=caseId%3d3052

Am I using the correct endpoint (API/bpm/archivedTask) or are there some other parameters I need to send?

I am developing against version 6.0.4

Thanks for your help