Git "bad sha1 file" error

Hello I have following error by git-fsck, witch cannot be cleaned by git-gc even in --aggressive mode. What can I do next to fix this repository error?

$ git-fsck
bad sha1 file: .git/objects/55/tmp_obj_a07724

From stackoverflow Artem Tikhomirov

• It's not a simple answer, sadly. But this might help:

  Recovering from repository corruption (from the Git's user manual).

  From Jordi Bunster

• Err... tmp_obj_a07724 suspiciously looks like a leftover temporary file :)

  What happens if you simply move it away from the .git directory (after a backup of the whole thing)?

  From Damien Diederen