Sometimes multipart uploads hang or don\'t complete for some reason. In that case you are stuck with orphaned parts that are tricky to remove. You can list them with:
If you are doing multipart uploading, you can do the cleanup form S3 Management console too.
a) Open your S3 bucket
b) Switch to Management Tab
c) Click Add Lifecycle Rule
d) Now type rule name on first step and check the Clean up incomplete multipart uploads checkbox. Now you an type the number of days to keep incomplete parts too.
That's it. You can see these steps in attached screen shot too.